The Kia Optima is a regular passenger car (a sedan) meant for daily driving. The 2016 model mentioned has a 2.4-liter engine, and the trouble code in the story means the car’s computer noticed something it didn’t like. Mechanics use those codes to figure out what part might be causing the problem.
P0010 is an error code your car can store when it detects something wrong with how the engine times the intake camshaft. The host says this one is related to the motor that controls the cam phaser on a Kia 2.4L.
A cam phaser is what shifts the timing of the camshaft. When it’s called “electronic,” it means the car uses an electric motor to move it, so electrical parts inside can wear out or fail.
When a code says “circuit problem,” it usually means the car saw an electrical issue—like broken wiring, a bad connector, or a failing motor. In this case, it’s the motor circuit that moves the cam phaser.
A brush-style motor uses small contact pieces (brushes) to send electricity to the moving part. Those contacts can wear out or cause poor electrical contact over time, leading to failures.
In a motor, the armature is the part that spins and turns electrical energy into motion. The host is describing how the phaser’s internal copper contacts help power that spinning action.
VVT means variable valve timing, and a phaser is the part that changes when the camshaft opens the valves. The host says the purpose is the same, even though the electronic version works differently.
Variable valve timing is how the engine changes valve timing depending on driving conditions. The goal is to make the engine breathe and respond better across different loads.
PCM is another name for the car’s main computer for the powertrain. In troubleshooting, mechanics check whether it’s sending the right command to the part that should be moving or switching.
A picoscope is a tool that lets a technician “see” electricity signals. It’s used to confirm whether the car’s computer is sending the right kind of signal to a component.
Cam phasing is how the engine adjusts when the camshaft opens the valves. Changing that timing can help the engine run better across different speeds and loads.
An H-bridge is electronics that can make a motor spin one way or the opposite way. In troubleshooting, it explains why current can flow in different directions depending on what the car is trying to do.
A key cycle means you turn the ignition off and then back on. The car’s computer re-checks sensors and circuits during that process, so some error codes only appear after you do it.
An open circuit means the electrical connection isn’t complete—current can’t flow the way it should. That usually points to wiring, a connector, or the motor itself rather than engine “timing.”
The intake control motor is a small motor that moves something inside the intake system to control airflow. If the code says there’s an open circuit to it, the issue is likely electrical—like the wiring or the motor connection.
Code enable criteria are the exact rules the car uses to decide when to turn on an error code. Even if a problem seems likely, the code won’t set unless those conditions are met.
Electrical checks are tests the car does to see if the wiring and electrical signals are behaving correctly. Instead of judging the mechanical result, it looks at things like current and voltage.
Pulse width modulation (PWM) is how the car controls power by turning a signal on and off very fast. The “on” time changes how strongly the system is driven, and the computer expects certain electrical results.
Amperage is the amount of electrical current flowing in a circuit. The car may watch current draw to confirm the component is working correctly when it turns it on.
ECVT in this context is the name of the electric motor/actuator system the car is checking. The diagnostic looks at the electrical circuit in two situations: when the motor is off and when it’s running. That helps figure out whether the problem is in the control side or the wiring.
The power stage is the part of the electronics that supplies power to the electric motor. When it’s “off,” the motor should not be actively driven. Testing the circuit in that off state helps confirm whether the electronics are behaving correctly.
A waveform is a picture of how voltage changes over time. Some problems only show up as a pattern, not a single number. Using the waveform helps you see whether the motor control signal is behaving normally.
Think of it like an electrical “out and back” path: power goes to the motor, and ground is the return path. If either side is wrong, the motor may not work correctly.
Bias voltage is a small “test” voltage the computer leaves on the circuit. It helps the computer confirm the wiring and motor are still connected correctly, even when the motor isn’t being commanded.
They’re using two different checks: one while the motor is actually being told to move, and another while it’s not. That way you can tell whether the problem is in the command/drive side or in the wiring/motor electrical side.
Voltage drop means the voltage gets reduced as electricity travels through a wire or connection. If there’s too much drop, the motor may not get enough power to work correctly.
Scoping means using a test tool (an oscilloscope) to watch the electrical signal as it changes over time. It helps you see whether voltage drops when it should.
An intake actuator is a moving part that helps control airflow into the engine. If the computer can’t command it, the engine can’t get the right airflow.
Back feeding means power is sneaking into a circuit from the wrong place. So even after you turn the key off, the computer or wiring still gets power when it shouldn’t.
The “driver circuit” is the part of the car’s computer that powers a moving component. If that component pulls too much current, the computer’s output can get damaged.
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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.
This episode is brought to you by L1 Automotive Training and Keith Perkins. If you're looking
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over 60 hours of training videos on all those subjects and more.
When I first started out doing mobile, I utilized Keith's videos on module programming and J2534
in order to get my head wrapped around what I would need for the tooling, the computers,
the software setups, what kind of obstacles I would be up against when I'm out there programming
modules on cars, and it was a huge benefit to me. And I continue to use the training videos
that he has on his website. So I strongly recommend checking out L1Training.com. 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. I'll be your host once again for this week's episode.
Thank you so much for joining me. You got just me this week. I've got another case study for you
here. This one's pretty interesting. Definitely something strange. I don't know if I'll see
this one again. Maybe. Hard to say, you know, time may prove that this was a one off or it's
something that could happen more than once on these vehicles. But just for clarification,
this was at a shop where a listener of the show works. And so I want to give this technician all
the credit in the world. This was not a simple straightforward problem by any means. And this
guy is a sharp technician, a friend of mine. And I won't put his name on here. I don't know if he
wants it or not. He can claim credit in the Facebook group if he wants to. Anyways, you know,
figure that out. And just in all honesty, sometimes it's like, did you guys even really try?
That was not this situation. This is a really strange one. So I'll get into it. It's a 2016
Kia Optima with a 2.4 liter. And the code that is setting in this is a P0010, which is simply
just a circuit code for the ECVVT motor, which is basically just the electronic
phaser for the intake camshaft. Now, you may hear that and you may work on these vehicles,
and you might be like, well, this is a really common problem with some really known solutions.
Right. You can hop on YouTube and punch in Kia 2.4 P0010. And you'll have 20 videos of people
repairing this in various ways. But again, it is simply put in service information or the definition
of the code on your scan tool is, hey, there's a circuit problem with the control motor for this
electronic phaser. Now, this phaser, again, is going to use just power and ground to operate,
but it operates much more different than your traditional VVT phaser. And to be totally honest,
describing it over audio is not the best way to go on YouTube and watch some videos of these
electronic phasers and how they work. It's kind of a dynamic component. And it's interesting,
but it's still an electrical motor. It's got power and ground. Okay. It's got actual contacts on it.
It's got brushes, if you will. It's more like a brush style motor. And that can actually be
a point of failure within these. When you have your plug in that goes on to the actual assembly.
So think about the front of the engine. You got the front of the timing cover. You've got the sprocket
and you've got this electronic phaser. It's got an aluminum cap that kind of goes over the top of
this thing. And then at the top of the aluminum cap, you have a plastic piece that has the connection
for the electrical plug in, but it's also got two brushes that protrude inside of the cap to make
contact with this electrical motor. And on the front of the phaser and the motor,
you have, you know, basically just two copper rings that serve as the armature, if you will.
Not exactly set up that way, but that's the idea there is you're just trying to make electrical
contact to this component. And as it spins, you can still apply, you know, power and ground to it
to actuate it to move the camshaft. Right. The end result is the same as everything we've been
doing with variable valve timing is to be able to move the camshaft back and forth. All right.
Change the timing under different loads. That that's nothing new. They're just approaching it a
different way here. And these systems are highly problematic, as can be seen by all the YouTube
videos. If you go on, you can watch them. And they have lots of front failure points, right?
So the actual contacts themselves, the brushes and the contacts on the front can become damaged.
And you can actually see like chunks of the copper come off and clearly that's going to
cause a circuit problem. And it's also well known. And you remove this cap and you can
see the carnage and okay, hey, replace it. You can also have oil intrude into this cap. Now,
of course, there's supposed to be oil behind the timing chain, but not within this assembly.
This is electrical contacts and it's not meant to be in an oil bath. But there's a plug in the
center of this unit that can either come out or leak. And there's a whole TSB about it if you
look this up. And it's a known problem. Okay. Of course, you can have other problems like wiring
or an ECM failure, or, you know, maybe an internal failure of the solenoid,
any of that could happen. Maybe the contacts on the connector, any of that. But here's the deal.
This shop, again, being a sharp technician, and they have some pretty good resources of their own,
they've replaced all of that and still had this P0010 setting on this vehicle. So, okay. And here's
everything that's been replaced. And not willy-nilly, like, let's just throw everything at this car.
It's, hey, we replaced this, we still have this code. Okay. Well, let's go to the next component.
And they actually did find things that were failed along the way. They found a problem with the plug.
They found actual damaged contacts. And they even found that there was no control coming
out of the PCM for this circuit. Like they have a picoscope and they were looking at how it was
outputting, and the fact that it wasn't. And this was our first involvement with the car,
actually, was when they called us and they say, hey, we'd like to do a used engine control module
on this 16 KIA. Can you do that for us? And we can. And we cloned it. My guy Keegan cloned it.
He's getting really good at that stuff. So shout out to him. But that was our first call
onto this car is, can you clone this module? So we did, cloned it over, got it to him. And I
didn't hear anything about it immediately after until this week, when they called us and said,
like, Hey, we've been through just about everything on this car. And, you know, we're
still getting this code. And, you know, we've gone back in and there, they have some internal
resources, which directed them towards maybe this code doesn't actually mean circuit code.
Maybe it's referencing timing. Maybe it's something more dynamic than what you're
understanding, meaning that maybe there's a double meaning to the code, or some performance aspect
of the the motor or the cam phasing or not phasing will set this code. And so they went in,
they checked timing on this thing, a couple times, actually, I talked to the tech that did it.
He wasn't in the greatest mood about having to tear this motor apart multiple times just to say
yep, the timing is still on. And it was. So anyways, get into this vehicle. And I do have
the advantage here of starting fresh with this, of just like, I'm just going to take it at face
value what it is, I'm not going to consider any of the parts that had been replaced. I mean, I am,
but I'm not going to walk into it thinking that all of these parts are good. Obviously,
some things a problem. I'm just going to take it fresh like it would a normal problem and let
my tests guide me to what needs to be replaced. Rather than, and I do this myself too, I already
put that part on there, it's not the problem. And, you know, all of us that do this, we can get into
that and that's that can be, you know, a hang up or waste a lot of time. So anyways, I'm going to come
into it fresh. And I do find that this code is present. And it is consistent, which is nice.
It's not an intermittent thing. And one thing that I find with this code is that I thought that I
found was interesting and actually led me to being able to solve this in the end, was that this code
would not set when the vehicle was running, at least not the amount of running that I did with it,
but I don't believe it would have. And this took me a while a little bit to figure out, but I found
that this code would only set after a key cycle, meaning that you could run this thing for a period
of time. And, you know, up and down with the RPM, make sure that the phasor is actually operating.
And I actually did put a scope, not only looking at amperage, but both control sides of the motor.
It's a two wire motor, but it will move it in different directions. So you can see the amperage
go in different directions. And obviously, it's a H bridge style circuit, kind of like a
electric throttle motor where it can have ground on one side, power on the other,
and then flip flop them to move it the opposite direction. Anyways, I'm looking at that. So
I have three channels on this, and it's operating and the current looks good. And it's moving up
and down, not setting this code at all. It was there when I got there, running it doesn't set it.
But with a key cycle, this code sets. As soon as you start it back up, it's got the double zero
10. And you can clear it out. And it will not set again until you do a key cycle. So I tried
something here. I was like, okay, the key cycle definitely has something to do with it. I don't
know what that logic is exactly. But there's something there. So I tried just turning the key
off and then turning the key back on. And I get this code. And the reason I'm trying that is
because this is a circuit code, right? This is by definition in what Kia's description of this
code is an open circuit to the intake control motor, not a timing code, not a performance,
not delayed operation, a circuit code. So I was like, okay, well, if it's all it needs is a key
cycle, number one, that makes it easier to, you know, actually duplicate and to test. But yeah,
I don't have to run the motor. I don't have to go drive it. And it proves out to me pretty clearly
that this is definitely a circuit code. There's nothing else that is looking at for performance
or operation or whatever else. It's circuit, we got to look at this electrically. And that seems
to be the case. Okay, so cycle of that key. And it sets the code, you don't even have to start the
engine up, get that double zero 10 every single time. Now, if you don't cycle the key, you don't
get the code. If you run the engine, you don't get the code. And I'm looking at the scope and I see
the amperage going both directions, I see the control on both sides and flip flop depending
on which way it wants it to go. And all of that looks good to me. Now, do I know perfectly exactly
what it should look like? No, not necessarily, but it looks, it looks like the motor is moving. And
it would appear that the computer's happy with it while the engine's running, or at least while I
just hold the key in the on position. But especially while it's operating, it looks pretty good. And
it seems to be happy with it. And it's operating the circuit. It's definitely not an open circuit.
Like this thing is actually operating. And, you know, it's all new parts. So it should be operating.
But something with the key cycle is what's triggering it. And that's what I've got to figure
out. So I did look a little closer at the code enable criteria and what actually sets this code.
And sometimes there are codes like this, where there's more to it than just the definition of
the code. And you got to dig deeper into service information. And hopefully the manufacturer
provided you with something that explains what it's actually looking for, what's making the
module happy or unhappy. And we all know there's lots of applications and scenarios and codes and
modules and circuits where they don't share that with you. It's a really vague reason why code sets.
It'll be like, you know, the measured value differs from calculated values or predetermined values.
But it doesn't tell you what those are. And gazillion examples of that. But sometimes they
do provide you with helpful information that you can use to try to figure out what's going on. And
I won't say that this led me exactly to where I needed to go. But it got me thinking about it at
least. And so here's the deal. When you go into the code, you look at the DTC detecting condition.
And this is right off of all data, you probably get it through Identifix or whatever service
information you're using. So this isn't anything special. Just search the code in there. There's
two cases that are under DTC strategy. Okay, and it says both of them, their electrical checks.
Okay, so case one, I'm not going to read it verbatim, but essentially what it's saying is,
after a certain pulse width modulation to the motor, it expects a certain amperage
amount on the circuit. Okay, so we commanded the circuit on. This show is brought to you by
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this out. The link is in the show notes. There should be a certain amount of current makes
sense, right? If there's not, it determines that to be an open circuit. Cool. Case two,
it is looking at the circuit when it is not commanding the motor and it doesn't give you
any specifics right here, but it's saying that it's looking at the circuit when the motor is off.
And again, not really anything beyond that. And actually it's sort of vague in its definition
here. It says the power stage of the ECVT motor is off. And then it's saying that the voltage
after the ECVT relay is between 10 and 16 volts, power stage off delay time plus system delay time
longer than 0.2 seconds. So to be totally honest, I read that. I'm like, I'm not really sure what
that means, except for it seems like it's looking at something when the motor is off. And by motor,
I mean the electric motor, the actual actuator, it's looking at it. Now that could be when the engine
is off, maybe it's while the engine is running, but at the very least I get that it's looking at
this circuit in two different states. When it's operating, I'm looking for current. When it's
off, I'm looking for something, but it doesn't define exactly what that is. Now, if you go to the
component inspection part of the DTC, and if you look up this code within all data,
it'll have different sections. And one of them is component inspection. And the component
inspection has you actually do some circuit checks for this code. And it provided some useful
information. And I think this will be useful for you if you look at these. You can also find this
on identifix to broken down into more of like a real world test. But they have it in service
information. But you've got to pay attention and actually go through the steps to find it.
But essentially what it's saying in service info is if you look at either the positive or the negative
side of this motor, and I realize they can be flip flopped. But if you look at the positive
and the negative side, the two wires that go to this, they should each read 3.6 volts when the
motor is not being operated. Now, if it is being operated, you'll see the voltage move. And they
actually have a waveform of that. Now, if you unplug this, and this is something that they don't
include in service information, but it is an is I'm sorry, it is in identifix, you'll see 11 volts
on one side on the positive side, and you'll see 0.5 volts on the negative side. Okay, so what does
all this mean here? And this took me a little while to figure out. But essentially what this is,
well, when the motor is being operated, you're going to see voltage, you know, being applied
to either side, you're gonna see amperage going through it, right? It's a, you know,
two wire power ground circuit that's pretty straightforward. And it's got a pulse with
modulated driver to do it. So look for that when it's operating. And I did, it looks great.
But when it's off, meaning when it does not want to command that motor to move at all,
there will still be a voltage, there will be 11 volts on the positive side and 0.5 on the other
with it disconnected. Plugged in, you have 36 on both sides, approximately,
pretty close to that, and says you should expect that in service information. What does that mean?
That means that this has a bias voltage that comes out of the ECM, goes through the motor,
drops across the motor, comes back to the ECM, and it is expecting a certain amount of drop,
and it's expecting 3.6 volts on both sides. Now, is it monitoring both sides? For sure,
I don't know, probably it's hard to say, but it is monitoring that circuit. And that's case two.
That's the, we are not actuating this motor, but we're using a bias voltage to make sure that it
is still intact electrically. So there's a two cases, we look at amperage when we're operating,
if it's not there above a certain pulse with modulation, we said, hey, there's an open circuit.
And we look at the circuit when it's off with a bias voltage, looking for voltage drop,
if that's not where we expect it to be, we set a circuit code. So that's pretty straightforward.
Okay, now what do I have on this car? Plugged in, I have 3.6 volts on both sides.
Unplugged, I have 11.5. Operating, I have amperage. Now, is it the exact amperage? I don't know,
but it doesn't set running. So I didn't dig too deep into that. And the motor seems to be moving,
seems to be functioning. Now, where do I go with this? And they had all been through this too.
He'd looked at all this, he had gone through this, and, you know, they were struggling with it.
Okay, so looking at the circuit, and you can see this on the diagrams, it's not only a power feed
to the motor itself, there is also a relay that provides power to the ECM for this circuit to
work. And you see this a lot of like high current devices that get run by an engine control module
or module of any type, where they'll have their own dedicated power feed with a dedicated relay
that provides power to them. And this is one of them. So there's an ECVVT relay,
which the ECM commands, but it sends power to the engine control module, and then through a
rail on the inside of that module, it then applies that power to the motor using some drivers,
depending on the direction it wants to go. Okay, so I said, well, I'm going to check and see what
this relay is doing. Now, why am I going in this direction? Well, I've assessed the circuit,
they've assessed the circuit, it looks okay, I don't see any problem with it. So what else do we
have left here of this system that we could check? Well, there is this relay that feeds power in.
And my first thought was, maybe this relay is not feeding the correct amount of power to this,
maybe the volt, maybe there's a voltage drop was what I was kind of thinking. And I was like,
well, I'm just going to check it and see what happens. But I'm also interested to see what
happens during the key cycle. Now, I was looking at the output side, and that 36, 3.6 volts drops
to zero, approximately five seconds after you shut the key off, turns back on when you turn the key
on. Okay. But I want to see what happens on this input side from the relay. And this is where
it actually got me somewhere that I needed to go. So scoping that side, when I shut the key off,
I can see the voltage drop off on the output side. But it does not drop, at least not
totally on the relay side. It drops a little bit below, like, considering that battery voltage
when your key is on, and it would drop below, and it would very slowly slope down. And so,
there's still voltage on that input side. And I was, as soon as I saw that, I'm like, okay,
I am on to something here. And I was thinking is probably just a relay sticking. Okay, because
if you'd wait long enough, it would eventually trail down, but it was a period of minutes. And
that's not how relays work should be off pretty quickly. So I'm like, Oh, okay, this is just a
relay. So unplug the relay and still have power. Well, I should say, there, if I put it into that
state, right, where I shut it off, and I'm waiting for that voltage trail down, if I yank the relay
out at that point, I still have power there. And there's also two fuses that go to it between the
relay and the ECM pull those still have power, I unplug the ECM, and I lose power there. Okay,
now the question is, okay, it seems to be coming out of the ECM. But is there another circuit
that is feeding into that ECM? And I actually spent a bit of time here trying to figure that out
of, okay, is there any other, you know, power feed that's staying on a different circuit that's
affecting this circuit? I couldn't find it with the checks that I was doing, I was able to eliminate.
So there's two connectors on the ECM. And I unplugged one. And I still had the same symptoms.
I'm like, Well, it can't be any of those circuits. But as it turned out, it wasn't any of the circuit.
And I did begin questioning him a little bit more on the details of his tests for, you know,
each different scenario. And I was curious to know, like, was this the problem with the old one
exactly, like the way we're seeing it. And I was kind of thinking, maybe I cloned over a problem.
I've done that before, that's happened. This is a weird one, circuit problems generally don't get
cloned over. But anything's possible. But when I was talking to him, he said, Well, the original
ECM had no control over the motor, which is why we replaced it. We didn't just chuck it at it
really nearly like it had no output at all to the to the actual intake actuator. I was like,
Well, that's kind of strange. So luckily, they had the original one there. I'm like,
let's plug this one in. I should have thought of that sooner. I didn't. But this way it goes.
But I was like, let's plug this one in and see, do we have the same situation or not?
And guess what? We didn't. That power that looked like it was coming from the relay
dropped off after the five seconds. But that ECM had no control over the motor.
Whatever driver circuit was in there was dead. And so they correctly replaced that.
But the ECM they got had a different problem. This one had power that was back feeding onto
the input side after the key had been shut off. Now, why this was occurring, I don't know, these
circuits appear to be sensitive to these intake actuators. And I can say I own checked,
it was pretty low resistance. Now running, maybe that changes a little bit, but they're pulling
some good amperage out of these. And of course, a driver circuit for something that's pulling a
lot of amperage is going to be susceptible to damage. And that seems to be the case here.
Almost every part of this system seems to be susceptible to failure, but the ECM included
in that. But we had one where the driver was completely burnt out, not actuating at all.
And then we had one that although it was actually that motor, it was back feeding voltage onto the
input side. Okay, so two different problems, two different ECMs. Now, why was it setting
an open circuit code with this happening? And that one's a little tougher to find. But my guess
is, because there was still power on the input side, like it would appear to be coming from that
relay, especially to the module, that it continued its logic of looking at the output side, even after
it dropped to zero, right? Because after five seconds, that voltage going to the actual intake
control motor would drop to zero, as it's supposed to. But it was still having voltage
on the relay input. And my guess is it's a comparative value, and it was still looking to
see that 36 it didn't. So it flags the code. And that's why you needed the key cycle
for it to happen. I can't say that with 100% confidence, but that's my best understanding
of what's going on there and how it interpreted a shorted power feed on the input
side as an open circuit on the output side is just that it's programmed to look at that voltage,
and it wants to see 36 as long as it's being fed power into the module. Again, my best
guess there, but it makes sense with what we saw. So they get a brand new ECM from Kia,
which by the way, was not an easy thing to do. They would have done that in the first place,
but they were in back order. And there just happened to be one that somebody ordered and then
didn't end up buying. And so they really get that we put that in there, we programmed it up,
and all good, no problems, system works great. So that was it. Anyways, I hope you found that
interesting. I hope that transferred well, audio only. I haven't done like a real technical
electrical explanation recently. So you'll have to let me know if that transfers well enough in
your mind. But you know what, like, it's good to really push your understanding of things like
electrical circuits. Like, can you envision it without a diagram? If you can, you're probably in
like the upper echelon of diagnostic technicians. And I'm serious about that, like having a good
mental model about this stuff. I think it's really important. So if you can listen to that and you
can picture, oh yeah, okay, 3.6 volts and 12 volts. That's awesome. But maybe you're like,
Sean, this doesn't make sense on a podcast. Like, let me know. Honestly, I could put some more effort
into videos. I just, I haven't done that. But anyways, that's where I'm wrapping this one up.
I've been talking long enough. Thank you so much for listening. Always appreciate it.
With that out of the way, let's get out there, start fixing the world one car at a time.
About this episode
A 2016 Kia Optima with a 2.4L engine keeps setting P0010, described as a circuit issue for the electronic cam phaser motor. The host explains how the ECVVT control is a brush-style, H-bridge-driven two-wire system, why the code only appears after a key cycle, and how service tests use PWM command, expected current, and bias-voltage/3.6V checks. After scope and relay/ECM power tracing, the root cause points to driver/back-feeding behavior, resolved with a programmed ECM.
This week on the show I share a case study on a 2016 Kia Optima 2.4L that's setting a P0010 in the ECM after multiple components have been replaced, including the ECM. This is a common code for these vehicles and they have multiple failure points in this system. This car turned out to be something more interesting than the typical fault.
