check Engine light but no engine faults read

EricEE · Mar 20, 2016

My 2012 Passat TDI recently threw a check engine light at 55K miles.
The only maintenance on it has been dealer oil changes and regular service up until the last one where the free service ran out and I had to do it myself. I cleared the service interval (after the oil/filter change) via the instrument panel and then did a fillup up with adBlue when that indicator showed on the dash.

I just read the fault codes via a ross-tech scanner which I have had for some time but I have not really used it much. This is the first time using it for reading fault codes. The only codes that showed are related to passenger side window motors which both work fine. When I clear those codes, the fault comes right back.

Q. Will it show the check engine light for window motor faults?

nord · Mar 20, 2016

Window motor will not set a CEL. Check your brake lights. Yup! I'm serious.

Vince Waldon · Mar 20, 2016

nord said:
Window motor will not set a CEL. Check your brake lights. Yup! I'm serious.

I think you may be thinking about a flashing glow plug light?

EricEE · Mar 20, 2016

Yeah, break lights were good. But the CEL is cleared by what I did with the scanner so I'll wait and see if it comes back. Thank you for your input.

sandmansans · Mar 20, 2016

EricEE said:
My 2012 Passat TDI recently threw a check engine light at 55K miles.
The only maintenance on it has been dealer oil changes and regular service up until the last one where the free service ran out and I had to do it myself. I cleared the service interval (after the oil/filter change) via the instrument panel and then did a fillup up with adBlue when that indicator showed on the dash.

I just read the fault codes via a ross-tech scanner which I have had for some time but I have not really used it much. This is the first time using it for reading fault codes. The only codes that showed are related to passenger side window motors which both work fine. When I clear those codes, the fault comes right back.

Q. Will it show the check engine light for window motor faults?

Hey eric.

Did you do a full scan or did you just scan for DTC? A full scan might show your fault.

Sent from my VS986 using Tapatalk

nord · Mar 20, 2016

Correct about the GP light. I'm getting old.

Vince Waldon · Mar 20, 2016

nord said:
Correct about the GP light. I'm getting old.

...as are all of the rest of us...

OP to answer your actual question: as far as I know the purpose of the yellow light is to tell you that one or more codes have been set and it's time to find a scanner and see what they are. "Codes" meaning any code, as opposed to only engine-related codes. So, also AFAIK door module codes will trigger the light... which will go off when the codes are read and cleared.

If memory serves VW refers to the light as a "MIL" (Malfunction Indicator Lamp) rather than a "CEL" (Check Engine Light) and that may be partly why.

EricEE · Mar 23, 2016

OK, well after clearing all the codes, and driving a bit I got the MIL/CEL to return.
In addition to the window motor codes (which I think are just complaining about a lack of baseline; wish I knew how to clear this for good) I also got an engine code back.
12642 - Change Air Cooler
P026A 00 [237] - Efficiency Below Threashold
I found another thread which seems to talk about this code. The thread has no good resolution yet. People are having sensors replaced but the code comes back.
Thread:
https://forums.tdiclub.com/showthread.php?t=428953&page=2

compu_85 · Mar 23, 2016

Have you had any heater core issues with your car? If the same gook that plugs the heater cores got into your intercooler it would cause that fault. Or if the intercooler loop water pump failed.

-J

EricEE · Mar 23, 2016

I have not. The dealership talked about two things. Cleaning gunk off a sensor (did not verify gunk was actually there) and flushing intercooler. I'll keep you informed. He indicated it might be related to short trips which I know Diesels in general do not like.

edit: oh, he also said the codes relating to the window motors would work themselves out over time (with window usage) if they are functioning correctly.

Den · May 19, 2016

Fault codes

Well the last time i had the Passat in for the normal service they said the alignment was out, WHAT on a new car??? was it not checked at the factory? had to pay to have it done, not happy, and at about 150 miles the add blue light came on. had to drive to dealer to get that fixed, a sensor, now i just got the next service and i have the following fault codes, steering, tire pressure,ABS, ESC, and air bag. What can a tech do to have this problem after car is serviced or is it just a fluke. This is getting aggravating. It's a hour to the dealer and an hour back time i can use for other important things.
Any one else having these issues?

aja8888 · May 19, 2016

Well, the "your car is out of alignment" gimmick is now spreading to VW? Our local Hyundai dealer does an alignment check on all cars coming in for service and tries to sell the "fix" for $129.00! What a joke! It's rare when any car can be in total alignment when even low tire pressure on one tire can make it slightly out of spec. It's a money grabbing trick.

Dealers are hurting and looking for ways to suck in folks. They tried that alignment crap with our Hyundai Santa Fe when we had it in for the recall on a defective axle. I told them they took it apart to pull the axle and they should align it. Know what, it really was OK after I said that to them.

check Engine light but no engine faults read

EricEE

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