A steering angle sensor tells the car how much (and which way) you’re turning the steering wheel. If it’s wrong, the car may think you’re turning when you aren’t—or not turning when you are—so warning lights or stability control issues can happen.
Resetting or relearning is like teaching the car where “straight ahead” is again. After certain repairs or power interruptions, the sensor can lose its reference point, so the car needs a calibration routine to get accurate readings.
Car
2008 Volkswagen GTI
They’re using a 2008 Volkswagen GTI to show what happens when the steering-angle sensor loses its calibration. If the battery is disconnected, the car may need to relearn how the steering wheel position relates to the wheels.
The Volkswagen Golf is a small car that’s made for everyday driving, usually as a hatchback. The GTI version is a sportier version of the same basic car. The podcast mentions an older 2008 GTI, likely because older cars can start having more repair and warning-light problems.
They also mention a 2021 GMC Terrain as another example. The point is that steering-angle sensor problems and reset steps aren’t identical across every car.
The segment explains that disconnecting the battery (or losing battery voltage) can cause certain European vehicles to lose stored calibration for the steering-angle sensor. That’s why a shop can accidentally create a new diagnostic problem when doing unrelated work that requires battery disconnection.
This sensor measures how much you’ve turned the steering wheel. If the battery is disconnected, the car can forget the calibration and may need to relearn it so driving safety systems work correctly.
An angle reset is the step where the mechanic tells the car to re-learn the steering sensor. It usually involves reconnecting the battery and then following the car’s instructions for turning the wheel.
The relearn process is the diagnostic workflow used to get the vehicle’s modules to accept the steering-angle sensor calibration. In this case, even replacing the steering angle sensor didn’t allow the car to pass the relearn, suggesting the issue was procedural/diagnostic rather than purely parts-related.
An aftermarket scan tool is a generic device for reading codes. The point here is that some resets require the right guided procedure, not just a basic tool that can communicate with the car.
The steering angle learn is a guided reset procedure. You turn the wheel a certain way and then drive briefly so the car can confirm the sensor calibration.
“Modules” are the car’s computers that control different systems. The steering sensor reset may need to be run in the right computer(s) in the right order.
Basic setting is the first part of the steering sensor reset. It involves turning the wheel and then doing a short drive so the car can learn the correct relationship.
The ABS module is the computer that controls anti-lock braking. On this GTI setup, it also plays a role in getting the steering angle sensor to “learn,” so you have to run the procedure through the ABS system.
Term
Otis
“Otis” is referenced as a factory diagnostic tool used to guide technicians through module-specific initialization procedures. The host contrasts it with aftermarket scan tools, emphasizing that the correct module path matters for the steering angle learn.
A “sensor learn” is a diagnostic procedure where the vehicle’s modules calibrate a sensor after service, replacement, or certain fault conditions. In this case, the steering angle sensor learn must be performed through the correct module (ABS) so the data stream updates properly.
Electric power steering uses a motor to help you turn the wheel. Since it’s computer-controlled, it may need calibration steps so it understands the steering position and limits.
“End stop learn” is an additional calibration step for electric power steering that teaches the system the steering limits (end stops). The host notes it can only complete after steering wheel angle initialization, and attempting both in the wrong order can prevent completion.
Some relearn procedures require a specific “drive test” segment to complete, during which the control module verifies sensor behavior under real driving conditions. Here, the host realizes the end stop learn wasn’t completing because it wasn’t finishing on the drive-test portion of the routine.
CAN bus is the car’s internal communication network. It’s how different computers in the car share sensor data—like steering angle—so other systems can work correctly.
The clock spring is a coiled wiring part inside the steering column that lets wires stay connected while you turn the wheel. If the steering angle sensor is mounted behind it, repairs may require careful disassembly.
This is the computer in the steering column that reads the steering sensor. It then shares that steering information with other car systems through the car’s network.
This is the computer that manages power steering assist. If it can’t get correct steering angle data from the network, steering feel or related warnings can be affected.
Wheel speed sensors tell the car how fast each wheel is spinning. If one sensor is wrong or not reading, the car can think there’s a traction/ABS problem and may not complete other sensor setups.
The tone wheel is a ring with a pattern that the sensor reads to figure out wheel speed. If rust builds up on it, the sensor can get a messy signal and the car may think the wheel speed is wrong.
Some car calibrations require a short drive to finish. If the car doesn’t trust the wheel speed readings (like if one wheel speed is off), it won’t complete the setup and may reset the process when you turn the key off.
Rust can mess up the signal the sensor reads from the wheel. Instead of clean pulses, the sensor may see extra or distorted pulses, which can trigger fault codes.
A scope is like a high-speed graph of the sensor’s electrical signal. Looking at it can show problems like extra or distorted pulses that a basic code reader might miss.
The hub is part of the wheel assembly, and it can include the ring that the speed sensor reads. If that ring rusts—especially on the rear—it can cause wheel-speed readings to go wrong.
This is a type of wheel speed sensor that reads the tone wheel using magnetic effects. As the ring passes by, it turns that into an electrical signal the car can count to know wheel speed.
The ABS light is the car’s warning that something is wrong with the anti-lock braking system. But sometimes a wheel speed issue can still cause problems for other systems even if the ABS light never comes on.
The hub and bearing are the parts that let the wheel spin smoothly. If rust has damaged the tone wheel or worn the sensor area, replacing the hub/bearing (and possibly the sensor) can fix the signal problem.
When you replace a car computer (control module) with a used one, it usually can’t just be plugged in. It often needs to be programmed so it matches that specific car and its security settings.
The host is recommending a company that helps with programming used car computers. They’re described as offering support so the replacement part works correctly.
Tommy is described as doing a service that helps used car computers work in the right vehicle. The idea is to avoid compatibility/security issues after installation.
The host uses a Chevrolet Malibu example where the car needed an “all keys lost” procedure, but a hidden connector problem stopped the fix from working. The customer didn’t realize it because the key still worked in normal use.
“All keys lost” is what you do when the car can’t find any working keys. The car’s security system has to be re-learned, and if there’s a wiring or connector problem, the process can fail.
Term
backup transmitter
The backup transmitter is like a secondary way the car can recognize the key. In this story, it didn’t work because of a connector problem, and that only mattered during the key programming process.
The host also mentions a Toyota Camry as another example of a problem that wasn’t obvious until they tried to do a repair or programming step. It highlights how prior issues can block the process.
Twisted wires can mean someone connected or damaged wiring in the wrong way. If the car’s computer gets the wrong signal, it can behave incorrectly or refuse to complete tasks like key-fob programming.
Programming a remote means teaching the car to recognize a new key fob. The car often needs the ignition in a specific state while it learns, otherwise it won’t accept the remote.
Sometimes the car already had a problem before the customer brought it in. If that earlier issue wasn’t noticed, it can make the new diagnosis harder because you’re chasing more than one thing at once.
A subframe is like a strong metal platform the car’s big components bolt to. If it gets taken down and put back, it can shift things slightly or disturb wiring, which can cause new warning lights or sensor problems afterward.
A scan tool can read live numbers from the car. A PID is just the label for one of those numbers. If the steering angle number says “zero” when the wheel isn’t straight, something is wrong with the sensor reading or its calibration.
An alignment rack is a machine that measures how your wheels are pointed. Shops use it to adjust things so the car drives straight, but it may not correct sensor calibration problems.
Toe is how much the front wheels point inward or outward. Adjusting toe helps the car go straight and can reduce tire wear, but it doesn’t necessarily fix steering sensor “straight ahead” settings.
The zero position is the sensor’s idea of where the steering wheel is perfectly straight. If that reference is wrong, the car can get confused about how much you’re turning.
Modern cars need to know what “wheels straight” means. A scan tool runs a step-by-step routine to set the steering sensor’s zero point so the car can drive and steer predictably.
The intermediate shaft is the link between the steering wheel and the steering mechanism. If it’s put back at the wrong angle after being disconnected, the wheel can end up turned while the car thinks it’s straight.
U-joints are the flexible connectors that let the steering shaft bend while still turning. If the shaft is put back in the wrong position, the steering wheel may not line up straight.
The steering rack is the part that actually turns the wheels when you steer. If the connections between the rack and the steering column are assembled incorrectly, the car can get confused about how much you’re steering.
A pinch bolt is a clamp-style fastener that holds two steering parts together. If it’s tightened while the parts are rotated the wrong way, the steering can be “off center” and the car may read the steering angle incorrectly.
Misalignment here means the steering parts weren’t put back together in the correct straight-ahead position. When that happens, the car’s sensors may think you’re turning more or less than you actually are.
Center position means the steering wheel and wheels are straight ahead. If you take the steering apart and put it back together without re-centering, the car’s sensor may think straight-ahead is slightly turned.
This is a diagnostic check: turning the wheel slightly while observing whether the steering angle value changes. If the displayed angle doesn’t move, it suggests the sensor signal isn’t updating (due to misalignment, a disconnected connector, or a sensor fault), which narrows the troubleshooting path.
Centering the rack is lining up the steering so “straight ahead” is truly zero. If it’s off, the car may think you’re turning more/less than you really are, which can cause weird behavior or warning lights.
The intermediate steering shaft is a link in the steering column that helps connect the steering wheel to the steering rack. Some versions are designed to move a little for safety, so if it has too much looseness you can get clunks or alignment issues.
Certain steering shafts are built to slide and collapse in a crash. That movement helps absorb impact energy so the steering wheel doesn’t shoot forward as violently.
If you hear a clunk when driving over bumps, it can mean there’s looseness somewhere in the steering column. Even safety-designed parts can develop too much play over time.
GM (General Motors) is referenced as the platform where the speaker previously saw this intermediate-shaft clunk issue on early-2000s trucks and cars. This helps listeners connect the diagnostic pattern to a known family of steering-column designs.
Cars assume that when the steering wheel is centered, the front wheels are also centered. If a shaft is put back slightly wrong, the steering wheel can look straight while the car’s wheels aren’t (or vice versa), which can confuse steering-angle-related diagnostics.
Term
steering wheel angle positions
This is basically “how far the wheel is turned” versus “where the wheels are actually pointed.” If the connection is assembled wrong, those two don’t match up the way the car expects.
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Welcome to the Automotive Diagnostic Podcast.
We're going to explore ways to sharpen our diagnostic skills, find learning resources,
and hear from experts in the automotive field.
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and a ton more. Once you purchase one of these training seminars, you can access this at any
time that you want through your account at automotiveseminars.com. You can re-watch the
training a year, two years later, which makes this training even more valuable. I highly
recommend you check this out. The link is in the show notes. Hey, what's going on? Automotive
World, welcome to another episode of the Automotive Diagnostic Podcast. My name is Sean Tipping and I
will be your host once again for this week's episode. Thank you so much for joining me. I've got a
couple case studies for you today, both centering around the same subject and both recent vehicles.
It is kind of weird in this industry where things come in waves. I think anybody who's been fixing
cars long enough has experienced that. I know I have throughout my career is like, you will get
hit with three or four of the same job back to back to back or within a week or two, and then you
won't see that job for six months at a time. We just had that with some Mercedes keys. We've done
lots of Mercedes keys, but I think we went a good five, six months without doing any, and then last
week I had two of them. The same day we did two of them. That's just the way things work. These
other two jobs, although definitely different outcomes, it was centered around the same thing,
and well, no pun intended, but this is steering angle sensors or the centering of the steering
wheel. In order to perform the steering angle sensor, reset or relearn. Both of them ended up
being interesting reasons why they would not complete or they would not complete correctly,
but that's why I'm talking about it on the show. First one is a 2008 Volkswagen GTI, and the second
one is a 2021 GMC Terrain. We'll do the Volkswagen first, a little bit older. This problem or the
that's where I ended up finding the solution was by reading up on it and finding other people's
posts. You may have experienced this. You may be aware of this. If not, it is definitely something
that you do want to be aware of, and I'll explain the situation that the shop was put in, and it's
interesting how this wasn't necessarily a problem prior to being in the shop for a separate service.
So again, 2008 Volkswagen GTI, it came into the shop for something completely unrelated. I think
they were doing something with the transmission, but the battery got disconnected during that time,
and pretty well known on a number of vehicles, especially European ones like Volkswagen's,
Audi's, BMW's, they will lose the memory for the steering angle position sensor when you disconnect
the battery or you lose battery voltage. That's not anything new, not anything special, and this
particular shop and this particular tech that was working on it, he's a real sharp guy. He has no
shortage of tooling, and this is not anything new, but normally you would just do that angle reset
after the battery is connected and you're done with whatever you're doing, and then you move on
with your life, and that's it. This one would not complete, and he tried many different tools,
many different methods. They even tried a new steering angle sensor on this one and was not
able to get it to pass the relearn process, and again, he's using a number of different tools
that should have been able to complete this job, so it wasn't just like a block of an
aftermarket scan tool, which you can run into with Volkswagen and Audi stuff. He knew how to do
the actual learn, and there is some confusion on this particular GTI model when you go to do
the steering angle learn because you can run the learn or at least attempt to run the learn
in a couple of different modules, and in fact, there is a couple of different learns.
So what I mean by that is there's a steering angle sensor learn or basic setting, they call it,
where you are going to turn the wheel back and forth and then take it on a short test drive,
and that's actually the one you have to do first because there is a second learn, which is the end
stop learn for the power steering rack itself. Now, on this model, and it does depend on the
version of ABS that you have, but on this particular 08 Volkswagen GTI, the steering
wheel angle basic setting is done through the ABS module, even though you have an option to run it
through the power steering. Now, if you're using Otis, it kind of guides you there, you don't need
to know that. If you're using an aftermarket scan tool, it is important that you need to run this
sensor learn through the ABS module. Okay, and then again, it's going to have you do the basic
setting of that steering angle sensor, where you crank the wheel back and forth, and then you take
it on a short test drive. Now, this initializes the steering wheel angle sensor. And interestingly
enough, and this is something that you would want to know, if this steering angle sensor is not
initialized, and you look at the data stream in either the ABS or the power steering, you will see
zero degrees, regardless of the position of the steering wheel. Okay, so you without the sensor
initialized, you won't see it move, even if that sensor is good. And that's a little tricky, but
that's normal operation. Now, as I mentioned, there is another relearn to do in the electric power
steering, which is the end stop learn. Now, this can only be completed once the steering wheel
angle initialization has been done. And I didn't understand that immediately. And so I'm trying
to do, you know, both learns like, Okay, do I have to get one to pass before the other? Well,
turns out it is that steering wheel basic setting. So I kind of left the end stop learn
alone, because it wouldn't complete and neither would the steering angle sensor initialization.
But after doing some reading, you have to do the sensor initialization, then do the end stop
learn. So I'm pushing the end stop learn to the side, I'm focused on that steering angle position.
And I have Otis out, I'm using the factory tool. I'm running this a number of different ways trying
to get it to go. And I cannot get this to pass. Now, after attempting it multiple different times,
multiple different ways, what I ended up realizing was that it is not completing on the drive test
portion of the relearn. So as I mentioned, you begin the process, you're gonna have some lights
blank on the dash, I believe it's the ABS and it's not the steering wheel. There's a couple
lights that will blink during this relearn process once it's being active. And you follow the prompts
on the scan tool, you move the wheel, and then you drive and you shouldn't have to drive very far.
You know, a lot of times this can be done in a parking lot. It's not a huge distance, but it
needs to see the vehicle move in order to complete the initialization on this particular model.
It's not true of all Volkswagen Otis, some of them you can complete this step at a stand still,
but it needs to see wheel speed in order to complete this. And when I was attempting to do this,
could not get it to complete. Now, the tricky part was is if you cycle the key, the relearn
basically stops. And so at that point, you might think, okay, well, it's not the lights aren't
blinking anymore, is it complete? No, it just stopped. And you'll have the code that indicates
this number one. But if you go into the data stream for the ABS module, there is a data
pit that indicates the CAN bus signal of the steering angle position sensor, and it will say
steering not initialized or sensor not initialized. So it says it right there in the data stream,
the obstacle that you are still facing is that this sensor is not initialized. Now,
I did mention that they tried another steering angle sensor, which by the way is up on the column
behind the clock spring, and it's connected to the top of the steering control module or steering
column control module. And this steering column control module takes the data from the sensor,
puts it out out onto the CAN bus, and then other modules just receive it, such as the ABS module
and the power steering control module. So it is a message that's sent over a bus. So I tried
doing some coding or checking the coding of all three of these modules, steering column control
module, the ABS module and the power steering. I was wondering, maybe one of them lost the coding,
and that's what we're dealing with, not the case. And again, tried many different ways.
There's a couple different paths you can take through Otis to do this.
Nothing I was doing was getting me anywhere. So ended up doing some research to see what could
be the obstacle here, right? And also considering that this car didn't have this problem before
the battery disconnect. So although it's possible, you know, a broken part or something like that,
I don't exactly understand what disconnecting a battery would do to this. But what I ended up
finding when I did some searching online of these steering angle position sensor relearns
that would not complete was that a lot of people were having issues with the wheel speed sensors.
And particularly the problem was rust buildup on the tone wheel of these wheel speed sensors or
just a failed sensor in general. Now, a lot of the issues that I saw online, there were some
unidentified, there were some in basic like Google searches, but that there would be a wheel
speed sensor code, or just a like a wheel that is not reading correctly, whether it be just not
outputting a sensor at all, maybe you have the wrong size tire or a flat tire. And so the wheel
speed is different than the rest. And any of those situations would prevent the driving portion of
this from completing. So you needed all four wheel speed sensors to be reading correctly and reading
at all in order for the driving portion to complete. Otherwise, it would just not do it. And as soon
as you cycle the key, the process stops. So I pulled those up as data streams and I watched them
as I was driving, they all look good to me in the parking lot. All four wheels, when I'm going
straight, we're at the same speed, they go up, they go down, didn't see any dropouts on the scan
tool. And the tech, it actually looked at that too. He's like, yeah, I checked it and I didn't see
any issues with that. And so that seemed like a dead end at the time, but I was about out of time
for what I had a lot at that day. So I said, I'm going to research this a little bit more,
and then I'll come back the next day. And that's what I did. And I looked a little bit more deeper
into it. And I found a couple posts out there that were actually showing the scope captures
from the wheel speed sensors in this particular situation. And I saw one that you can see the
extra pulses or the interference from rust buildup on the tone wheels of these wheel hubs,
and particularly the rear wheel hubs seems to be the ones that suffer from this the most.
I'm sure you're familiar with the type of wheel bearing that has a round magnetic strip on it.
And that rotates past the sensor and generates the pulses. It's a magneto resistive style
sensor that outputs a digital just on off slight change in voltage. And the rust buildup would
cause these sensors to read in accurately. And it could cause just slight disturbances in the
waveform. So I texted the guys like, I'm going to come back tomorrow. The first thing we're going
to do, put this up in the air, we're going to scope these wheel speed sensors, spin them,
and see what we get. So we do that. And once we got this thing up in the air, we could see
on the tone wheel of the left rear wheel, it was really both rears, but the left rear especially
definitely had a noticeable buildup of rust on there. And it was even coming into contact with
the tip of the sensor, like you could tell the tip of the sensor was actually worn down
a little bit from the rust buildup on this thing. So I mean, right there, like, okay,
this is definitely screaming a problem. Let's take a look scoped it with the Pico. And you could see
when you were rotating this wheel by hand that there was extra teeth, right? So if you picture
a normal square wave where the high and the low pulses are in even length given, you know, a constant
speed of the wheel, there would be little extra teeth or a break in a tooth, which to the module,
when it's looking at that sensor, that is going to indicate a change of wheel speed,
okay, or just an air. Now, in this case, for this one, it wasn't sending a code,
it was still registering wheel speed, at least via the data pit that I could see in the scan tool.
But it was enough for the module to not see the correct wheel speed or to see enough of
a change in the wheel speed there, that it wasn't allowing this process to complete. Now,
didn't have any ABS light on, didn't have any codes, again, the data pairs looked okay. But
this incorrect output from the wheel speed sensor on the left rear, because of the rust buildup on
the tone wheel, was causing this to occur so that I could not complete the basic setting of the
steering angle sensor. So they got to replace the hub, the bearing, and then probably the sensor
on that one as well. And then the right rear is also a question mark, because it did have some rust
buildup. The fronts seemed okay, you can actually see the sensors as easily they go into the wheel
hub on that one. But they seem to have, you know, the correct output that we're looking for. But
in this case, was the vehicle completely functional? Now, he had a pre scan, and he had no codes in
the ABS. Did the customer have some issues with ABS lights popping up or ABS activations? Hard to
say, don't know. It definitely was not in, you know, correct working order before it came to the
shop. Is the system maybe more sensitive during this time when it's doing this calibration? Not
sure. Hey, have you ever been faced with the challenge of sourcing, installing and programming
a used control module in a vehicle? I know a lot of us have. It seems to be happening more and
more often today with the volume of control modules on vehicles, the cost of some new ones,
or even the availability of new control modules in some cases used may be the only option. So what
do you do here? I strongly recommend checking out SJ auto solutions and Tommy Oliva. Tommy offers a
cloning service for use control modules to make these things plug and play for the vehicle that
you're working on. In a lot of cases, he is also able to source the control modules if you're unable
to locate one for the vehicle that you're working on. But once you get connected with Tommy, he's
going to offer fantastic support from start to finish to make sure that that control module is
going to work in your application. He's also got tech support that he offers through his website,
along with some free resources there as well on information about used control module programming.
So make sure to check out SJ auto solutions. I can't recommend that enough.
It is a problem. It's visible. You can see it. We obviously didn't cause this. The shop didn't
cause this. It was there before, but because of something preexisting on the vehicle,
we now can't complete a process. And, you know, we run into this in the automotive world a number
of different ways. I had a case study a few months ago on a Chevy Malibu that we were trying to do
an all keys lost. And prior to the all keys lost, the car ran, it was fine, the keys worked. But
because there was pops build on a connector, the backup transmitter wouldn't work. And now it
wasn't going to work for the customer, but they had no idea because they just used the key in
the normal fashion. They're not using the backup slot. We get to a point where we have to do something
on the car and all of a sudden we can't do it because of a preexisting problem that wasn't
obvious to the customer, right? Or they just didn't notice. Same thing. Toyota Camry couldn't
program in a remote control. Somebody had taken the key in switch wires and just twisted them
together so that it always thought the key was in the ignition and part of programming a new
remote to the system is to have the key out of the ignition and it uses that switch to determine
that. So we couldn't program this remote, right? Again, preexisting symptom on a car that either
was ignored or just not noticed by the customer, the owner of the vehicle, but now prevents us from
being able to do part of our job. And that is real stuff. That happens. And as technicians,
we want to be aware that like, there could have been something wrong with this car to begin with
before we even started on has nothing to do with us. But now we have to figure it out, right? We
have to diagnose another problem in order to do the thing that we need to do on the car as far as
our service goes. And that can be a tough thing to explain to a customer. Luckily,
when you have visual confirmation, it's a little bit easier of like, hey, look at this rust build
up. This is a problem. Look at the pop in this connector. Look at these twisted wires. This
was an issue. You just didn't notice it because. So I thought that was pretty interesting. Again,
that one's a little bit older and well known. And so, you know, you may have run into that.
There's a few hits and identification, although most of those mentioned a code for the wheel
speed sensor. This one didn't have any. There definitely wasn't any circuit codes or anything
like that. All right, the next one is a 2021 GMC terrain. Now this one, the shop had the subframe
down in order to do a transmission before we got involved with it. And they got everything back
together, got the transmission programmed or whatever it was that they were doing. It may not
have actually been a transmission. I don't know, but they had the subframe down. That's the important
part here. And before they had the subframe down, there was not an issue and afterwards there is
an issue. So we can safely assume that they built this in. The question is how do we fix it? Now,
here is the issue. The steering wheel, when it shows the zero position is about 50 degrees to
the right. Okay, what I mean by that is if you go into the scan tool and you look at the steering
wheel position as a data PID, zero degrees, which should be a straight steering wheel, is off to
the right about 50 degrees. Now, they have been through this several different ways, right? They
put it on the alignment rack, they did the toe adjustment to make sure that everything was straight
there. They tried manipulating it. So you know, okay, let's center the steering wheel, we'll move
this here. Nothing they could do was getting the steering wheel to a straight position, though.
They also tried a bunch of different relearns for the scan tool. Okay, is this something where we
need to learn the zero position, it thinks it's over here, we need to tell it it's over here.
They went through all the tooling that they had, they were not able to do the learn,
it would either fail or it would pass, but it would still end up in the same position.
And so that's when they called us in, and they called us in for programming, they said, hey,
you know, we did this, we had the subframe out, the rack was disconnected. And now this steering
wheel is off in a 50 degree position. So I come in, and I try running the relearn that's available,
and it's a steering centering procedure. And it even says in the procedure, like,
you don't need to do this very often. But here's the steps, follow it. And so we follow it. And
what's interesting is, this steering centering position will air out if you have the steering
wheel straight. Okay, so the steering wheel wind up, go through the process, or, you know,
I end up in that straight position, it just airs. And they'll say like, device exceeds limits or
something like that. But if I put the steering wheel to the right about 50 degrees, and I can
watch the data pit and see that, oh, okay, this is the zero position here, then I'm able to get it
to pass at that point. So it's happy. It's like, okay, this is zero. All right, center it up. All
right. And then it passes the procedure, but you're still stuck with a wheel that's off 50 degrees.
So as I'm getting into this, I'm thinking, okay, well, the way they connected something up has to
be off in this case. And it's a 21 terrain, I've never physically had any of these components apart.
And so I was asking the technician, I'm like, when you had this disconnected, where did you
disconnect it? And they said it was at the base of the rack, right? So you have the steering column,
you have the intermediate shaft, which has a couple of U joints on it, that intermediate shaft
connects with a pinch bolt to the column, and then down at the rack itself. And you can actually get
to both of these bolts underneath the dash, you can see where it connects to the top of the rack,
you can see where it connects to the base of the steering column. And again, intermediate shaft,
a couple of U joints on there. And I asked them, like, can you put this on in multiple ways? Because
that's what I figured they did. They just misaligned this thing. And we need to get it, you know,
back to its center position. And they said, no, there's only one way you can put, you can put
the bolt on at the bottom. He's like, I didn't have it off the top, though. I'm not sure if that
one's splined or not. But at the bottom, it's, it's one way you can't mess this up. And so I
inspected it and I verified and like, yep, that's there's only one way to do it. So I looked up at
the top where it connects to the column itself. And I couldn't really tell whether it was a one way
deal or not. It looks like it looked like it had splines all the way around. So I actually ended
up disconnecting it here. And I wanted to do this for two reasons. Number one, I didn't know where
the steering angle was actually coming from. There wasn't any real info information about a
steering angle sensor, right? It has a clock spring, but I didn't see a diagram for a sensor. Now,
like in the Volkswagen that I just mentioned, the sensors up in the column. And I was wondering,
is this part of the clock spring on this vehicle? Or is it maybe in the rack? Maybe that's where
it's getting the steering angle position from, because you can look at it in different modules.
You can see it in the ABS module, you can see it in the power steering control module. But where is
that data coming from? Right? Because that might help me to determine what part of this is actually
out of misalignment. I have a feeling it's between, you know, the steering column and the rack, but
like, where's that measurement being taken? And then also, I just want to see, you know, maybe they
did get disconnected up top. And, you know, information was missed. They're not telling me
all of it. I don't know. But if we can just rotate that to be straight, put it back together,
that's what I'm going to do. So I disconnected here. And again, I do two things. I turn the
wheel slightly while I am watching my angle. And it does not move. If I turn the rack and the wheels,
the angle does move. So now I know that the angle is being measured in the rack itself. Okay,
cool. That's good information to know. Now, I look up at the connection to the intermediate shaft.
And to the base of the column, there's only one way to put this on. You can't screw it up. It won't,
you won't be able to slide it together because there's a big notch that only allows you to connect
those one way. And it's the same thing down to the base of the rack too. So I'm like, okay, well,
let me put this back together, because there is only one way to put this back together,
like you literally cannot put this into the wrong position using the pinch bolts on either end.
Doesn't allow you to screw this up like some other cars you definitely can. You can put it
on any which way and then you're off by however many degrees you missed it. And there was even marks
on both sides too, which I assume are from the factory. I don't know, maybe the technician did
them, but those are lined up. You could see that, okay, these notches line up, these notches line up.
That's, that's how these go on and they don't let you do it any other way. So
put it back together and kind of start fresh here. Now I know that the angle measurement is
actually being measured from the rack itself, but there is some sort of misalignment between the
steering wheel and the rack. And it doesn't appear to be the one component that you can take off
between the two of them. So I'm wondering, I'm like, did the rack get damaged? Is there something
bent? And so I had them lifted up and I'm looking at all the components to see, you know, did
mounting get screwed up or something? Or is there just something out of place? And everything looked
good. And I even had them drive it over onto the alignment rack. And we did the tow adjustment
together. Like I sat in the vehicle and I held the steering wheel in the straight position. I had him,
you know, tow up the wheels. And we're still in the same boat, right? You can, you can get the wheels
straight. But the rack still thinks that the wheel off 50 degrees to one side is zero when, you know,
it's off 50 degrees to one side. I did something else here just to see, I turn the wheel full stop
one direction and then the other and you can go one and a half full turns to the right,
one and a half full turns to the left on a normal rack and a normal steering wheel. And they even
said that they were like, we centered the rack before we put it back together here, we went one
and a half, one and a half, okay, right in the middle, here's zero. And the rack obviously, or
the rack should know where center is because it's got the steering angle sensor in it, right? And so
we made sure when we put this back up in here, it's in the straight ahead position. But the steering
wheel doesn't bolt up to it unless it's turned to the right. And with everything connected,
if you turn that steering wheel to the right, you can actually rotate it when it hits the lock,
that wheel rotates further than when you do it to the left, right? You can look at where it lines up
with the shell around the column. And when you go to the right, you can rotate it about 50 degrees
further. So I'm like, there is a misalignment here with how these are connected. But I didn't
understand where that could be based on what they were doing. Unless I was like, well,
maybe there is some damage in the rack. I don't know how that would have happened. But
something's goofy here. And so I was looking at that intermediate steering shaft one more time.
And I was going to take it off at the base of the rack, just to make sure like, it looks like,
you can see where the bolt goes through and everything. And it looks like it's a one way deal,
like you're not going to be able to screw this up. But as I was looking at it, these intermediate
shafts, they're two piece, and it slides in and out of one another. And the reason I'm very familiar
with this is if you worked on GMs back in the early 2000s, on the trucks and the cars, they would
have a really noticeable clunk over bumps. And what it ended up being was the intermediate shaft,
that sliding portion. And really, it's just, it's meant to collapse in the event of an accident
when, you know, the front of the vehicle gets pushed into the vehicle, that intermediate
shaft absorbs some of the movement rather than having the steering wheel, you know, get pushed
into your chest. And so they are meant to slide in and out, but there's a little bit of play between
them. And the fix was either to replace the intermediate shaft, or you could actually pump
them full of grease with the trucks and get the noise to go away. And we did some of that as
service. But when I would do those, you couldn't take those apart, meaning that you could take
them out of the car, you could film with grease, you can slide them, you know, in and out, but they
wouldn't fully separate at the end. There was a stop in there, I think the metal was actually
just pinched in a way where you couldn't fully slide them into two pieces. But I was looking at
this one, I'm like, I wonder if this one can. Now, the way that these two metal pieces slide
together is it has about six or seven ribs around. And then the lower portion of this intermediate
shaft splines into there, essentially. So I took it off of the base of the column.
And then I pulled, and then they pulled completely apart. Right. So now this intermediate shaft is
now in two pieces. And I'm like, I wonder if I rotate this one to the left, and I put this back
together. Are they going to slide in together? And it did. And then I put it back onto the rack.
And what do you know, the steering wheel is in the centered position. So what happened was when
they disconnected the intermediate shaft underneath the dash, those two pieces from gravity probably
slid apart. And when they were put back together, it was one notch off. And so there was a disconnection
from the center of the steering wheel and the center of the rack due to this intermediate
steering shaft being separated and put back together at the wrong index point. So I'd never
experienced that before. And I wasn't even aware that piece could come apart like that, but it
definitely can. So if you're doing one of those vehicles, pay attention, don't let it fall apart.
But maybe you're getting one after the fact that has a steering wheel that's off center by that
amount. Consider, hey, did someone have this apart? And even though the bolt up part of it,
you can't screw up, you can screw up how they go together if it comes apart. So I thought that was
pretty interesting. And I thought I'd share both of those on the show because they were a little bit
time consuming on both of them to figure out. But interesting how they ended up being steering
wheel angle positions within the same week. So that's all I've got for today's episode,
want to thank everybody out there for listening. With that out of the way,
let's get out there, set fix in the world, one car at a time.
About this episode
Two recent case studies dig into steering angle sensor relearns that wouldn’t complete—or wouldn’t “center” correctly. A 2008 VW GTI lost steering angle initialization after a battery disconnect, and the fix turned out to be rust-disturbed rear wheel speed tone rings that prevented the drive portion from finishing (even without ABS codes). A 2021 GMC Terrain had a 50-degree steering wheel offset after a subframe/rack-related job; the relearn only “passed” when offset, and the root cause was an intermediate steering shaft that had separated and reindexed one notch off.
This week on the show I share 2 case studies from the last week. Both are steering angle sensor relearns that won't complete, or won't correct the issue. First is a 2008 Volkswagen GTI that had the battery disconnected and won't learn the steering angle basic setting afterwards. The second is a 2021 GMC Terrain that has an off center steering wheel no matter what relearn or alignment procedures are performed.
