Pawlik Automotive Podcast Apr 6, 2026

2014 Mercedes C300 Ambient Air

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Car

2014 Mercedes C300

They’re working on a 2014 Mercedes-Benz C300. The owner thought the engine was misfiring, but the shop confirmed what was really wrong by checking the car’s stored error codes.

Term

misfire

A misfire is when the engine doesn’t burn fuel correctly in one cylinder. It can make the car feel shaky or stumble, and it may trigger warning lights.

Term

check engine light

The check engine light means the car detected a problem and saved details about it. A mechanic can plug in a tool to read the exact code.

Term

scan tool

A scan tool is the computer device a mechanic plugs into your car. It reads the stored error codes so they can diagnose the problem correctly.

Part

ambient air temperature sensor

This sensor tells the car what the outside temperature is. If it’s wrong, the car can get confused and may turn on a warning light or make the climate system act weird.

Term

transmission downshift

A downshift is when the car drops to a lower gear to give you more power. If it feels like a hard bang, something in the shifting logic or inputs may be off.

Term

Rescanning means checking the vehicle again with the scan tool after repairs or after new observations. It’s used here to confirm whether the fault codes return and whether the issue was truly resolved by replacing the sensor.

Term

front of the vehicle and front of the radiator

This sensor is mounted up front so it can measure the outside air properly. Being near the radiator/front area also means it can get hit by road grime or debris.

Term

climate control system

The climate control system manages cabin temperature by using inputs from sensors (like ambient/temperature sensors) and controlling heating and air conditioning. If a sensor is wrong, the system can command the wrong temperature behavior, even if the user selects a normal setting.

Term

air conditioning

Air conditioning (A/C) is used to cool the cabin and can also be part of how the climate control system regulates temperature. In this segment, the speaker notes that with A/C on, the cabin stayed freezing, suggesting the system wasn’t receiving correct temperature information.

Term

vehicle computers

Cars today have multiple computers that talk to each other. If one computer gets the wrong info, it can lead to weird behavior in other parts of the car too.

Concept

computerized

Cars today rely more on computers to manage everything. That means sensors have to give correct information, or the car may complain with an error.

Term

all of data and all the inputs

The car’s computer uses lots of information from different sensors. If one piece of information is wrong or missing, the car can log an error even if the rest is okay.

Concept

cheap, easy fix

They’re saying this problem is usually not a big, expensive repair. Many sensor replacements are simpler than fixing major parts of the car.

Company

Pollock Automotive

They’re recommending a specific repair shop in Vancouver called Pollock Automotive. If you’re dealing with a similar sensor/code issue, that’s who they suggest contacting.

LIVE

Hi, it's Mark Rossard.

I'm here with Bernie Pawlik, Pawlik Automotive in Vancouver, Vancouver's best auto service

experience.

We're talking cars.

How are you doing, Bernie?

I'm doing very well.

So today's guest, our first guest is the 2014 Mercedes C300.

What was going on with this vehicle?

So the owner had complained that the engine sometimes had a little, what felt like a misfire.

The check engine light is on and also I believe the climate control system wasn't quite working

properly either.

So shifting, misfiring, climate control could be a big issue, perhaps.

Exactly.

Yeah.

And where did you find, well, let's go to the pictures.

We'll jump in right off the bat because this one is interesting.

We can also talk while you're pulling the pictures up of the diagnostic process.

Sure, please.

So there's the car.

It's over 10 years old now, but still looks brand new, 105K.

So it's still a young car.

It's got lots of life left in it, good shape.

So diagnostic process, of course, do a full vehicle scan with the scan tool and we found

only one code in the engine, even though the client has said it was a misfire.

The only code was for a ambient air temperature sensor.

And the sensor basically measures the air temperature of the outside air.

Nothing to do with the engine.

It really just feeds information to the vehicle.

I mean, I guess it does serve the engine in some ways, but it's mostly for the climate

control system and doing a little further reading along the scan tool of the data.

The sensor was reading minus 128 degrees.

I think that was Celsius, whatever it is, exceptionally cold temperatures don't even

exist on this planet.

So it was way out of range, to say the least.

And your car is not running very well at that temperature.

No, exactly.

So my technician who worked on it goes, well, there's no misfires.

And we thought, well, you know what, the owner's complaining about.

So I took it for an extra long drive and I didn't feel any misfires, but I did notice

going up some hills when the transmission would downshift, it would make a really hard

banging, hard transmission shift.

So I go, well, that doesn't feel right.

Anyways, rescan it again.

Yeah, that's the only code that was there.

No transmission code.

So we replaced the sensor and basically cured everything.

Here's the part here.

There's the part.

Where did this live?

It lives basically at the front of the vehicle and front of the radiator.

Actually, I didn't change it myself, so I can't say exactly, but that's where they

typically sit somewhere outside, away from the heat of the vehicle, where it can

actually capture the air temperature properly.

And after that was replaced, well, I did notice when I was driving the vehicle,

the climate control system was interesting.

Like when you turn it to say 24 degrees and you have the air conditioning on,

this is Celsius, 24 degrees Celsius.

The car should be warm inside, but it was freezing cold.

And yet if you turn the air conditioning button off, then the car would get warm inside.

So clearly it wasn't working as soon as the sensor was replaced, the climate

control system adjusted the temperature properly.

I took it for a drive.

The transmission didn't seem to shift badly at all.

Any speculation as to why this particular sensor might cause a misfire

or transmission problems?

The vehicle computers, they'll talk to each other.

They gather information and they make assessments on certain things, like the

temperature is this, you know, so it's thinking, OK, the temperature is really

cold out, it needs to operate this way.

It certainly makes sense for the climate control system.

But even then, it wasn't responding in the way you'd think it would.

But it's getting wrong information.

And so, you know, with our brains, if we get wrong data, we make wrong decisions.

Cars are kind of like that, too.

2014.

So is this an issue that's possibly going to crop up more as cars get more and

more computerized being 2026?

Well, the ambient air temperature sensors have been around in cars for a very long

time, and sometimes there'll be codes for them and they don't work properly and

they don't really cause any other issue.

This one is kind of the more extreme one I've seen, but it goes to show that you

need to have everything proper, all of data and all the inputs.

Unfortunately, this is a really cheap, easy fix compared to some sensors.

Sure.

So if you're looking for service for your Mercedes in Vancouver, the people to

see are at Pollock Automotive.

You can reach them online at PollockAutomotive.com.

You can book your appointment right there, or you can call them at 604-327-7112

to book your appointment.

You have to book ahead.

They're always busy, screaming busy.

Pollock Automotive in Vancouver, BC, Canada.

Thanks so much for watching and listening.

Thanks, Bernie.

And thank you, Mark, and thanks for watching.

0:00

4:18

2014 Mercedes C300 Ambient Air

C-Class Mercedes C300

2014 Mercedes C300

misfire

check engine light

scan tool

ambient air temperature sensor

transmission downshift

rescan

front of the vehicle and front of the radiator

climate control system

air conditioning

vehicle computers

computerized

all of data and all the inputs

cheap, easy fix

Pollock Automotive

About this episode