Engine Control Module (ECM) anomaly

[Bob Mc]

2015 Passat TDI; 56,000 miles; smog upgrade; original owner.

Accelerating onto I-90 about 5 miles from home, glow-plug light began flashing and vehicle seemed to lose power. Got off the freeway soonest, owner's manual said ECM go to dealer. I left the engine running while checking poorly designed owner's manual to find warning light and meaning. Drove the gutless car home, including uphill mile of 10-percent grade, and parked it. Used VW CarNet to get health report, it said no problems. Started car and warning light remained off. Went out today with a scan tool, found no faults or codes. Drove around neighborhood, it seemed normal. Took it out for a few miles and hills, seemed normal. Did not try freeway run. WTH?
The day before the ECM problem, we had an electrical storm, with a nearby lightning strike (but not the vehicle). Could a pulse have induced a module glitch that reset once the power to the module had cycled? Asking advice: monitor closely, or panic and take car in? I believe the ECM is under the VW "we cheated "extended warranty, but if it hasn't set any codes, then isn't the presumption that all is good?

Thank you for any relevant advice.

I had a flashing light pop up the other day shortly after starting the car. Pulled right into a gas station and shut off to search what the light was. Engine control module, bring to authorized service center. This was saturday afternoon so I turned it back on and brought it home. The trip home, no issue, no light. The car was running seemingly normal in first and in second like it didn't want to build boost up around 1800 RPM. The car is under warranty, going to call a dealer today and see if they want me to bring it in or not as it has seemingly gone away.

anyone else experience anything like this?

 

[740GLE]

a VW scan tool will show the stored code, i'm guessing you're using a generic scan tool? Until you read with a proper scan tool (ODB Eleven is nice and cheap, VCDS is even better but costly) its a matter of guesses and marking it up to a random fluke.

Best of luck.

 

[oilhammer]

The generic scan tools won't really help in this situation.

 

[Bob Mc]

Thank you, for taking a look. I used an OTC 3209 OBDII, ABS & Airbag Scan Tool. I don't use a cell phone, so it appears that the ODB Eleven tools wouldn't help me. I guess if it glitches again, I'll let the dealer worry it out. I believe the ECM is covered under the VW extended warranty agreement, because if the ECM is bad, the vehicle is unlikely to meet its emission standards (wink-wink).

 

[740GLE]

a dealer will be able to scan it but seeing there's no current issues they'll charge you the diagnostic fee as there's nothing to replace until the CEL is stuck on.

 

[JELLOWSUBMARINE]

a dealer will be able to scan it but seeing there's no current issues they'll charge you the diagnostic fee as there's nothing to replace until the CEL is stuck on.

Not necessarily, there can be a DTC stored without a CEL on. IF thats the case they are oblligatted to apply the $0 deductible under warraanty, if the repair is under warraanty.

Note
Emissions warrenty

 

[740GLE]

But if the code is for say intermittent issue so for VNT implausible signal causing limp mode the dealer will most likely state "can't reproduce any faults, ran adaptation of VNT, all passed", they can't replace/charge VWoA, please pay us for our time.

At least that's been my experience.

 

[JELLOWSUBMARINE]

But if the code is for say intermittent issue so for VNT implausible signal causing limp mode the dealer will most likely state "can't reproduce any faults, ran adaptation of VNT, all passed", they can't replace/charge VWoA, please pay us for our time.

At least that's been my experience.

Yeah that stinks and that's the chance you have to take. So going in well armed with the best knowledge possible and a good relationship with a good dealer can be all the difference sometimes. Dealers now won't warranty a thing w/o a code set, it didn't always be that way. Ha. Can you imagine having to actually diagnosis an issue based on symptoms and not just a code? Or even no code pre OBD? Yeah I remember...****!

Anyway good luck, its worth frakng the chance on coverage IMO

 

[740GLE]

finicky door lock module was the one that opened my eyes that dealers don't actually care about the problem when VW warranty is concerned. My lock module had tons of stored intermittent codes, but worked when at the dealer, I walked away without a fix. I can't really blame them but still.

 

[JELLOWSUBMARINE]

My lock module had tons of stored intermittent codes, but worked when at the dealer, I walked away without a fix.

If you had an *issue and the stored codes varified the complaint (assuming your problem was a covered item under, say the say bumper to bumper coverage). That would be wrong on the dealerships side. A good dealership would cover a verifiable probablem within the warrrenty, even without a code.

My example is a Ford I once owned that would have very intermittent no starts, varified by multiple tow truck documentation. No codes were ever present. The dealer supposedly could never duplicated General common sense (to me anyway) pointed to intermittent no fuel. I suggested they swap the relay. They covered that... Never failed once afterward.

My point is a good dealer and a legitimate complaint that falls under coverage is worth pursuing.

 

[740GLE]

agreed, each dealer is different and how much they are willing to go to bat for you. I was able to get the center console arm rest replaced is was locked open and easy to point as a failure.

 

[Bob Mc]

I appreciate everyone's input on this, and related discussion. A VW dealer that I had worked with for 25 years recently left VW to focus on their Toyota/Subaru business, and told me they couldn't cover me on warranty work. They had been great to me, never pushed services. I had a 95 VR-6 Passat with about 110,000 miles with a torn CV-boot, a few very slight gasket leaks (not yet showing drips on the ground), wondered about the clutch and shocks. Anyhow, I asked "how much" to fix the items when I took the car in for service. When I went to get the car after the oil change, the manager met me in the lounge, went over all my 'concerns', and said "the car is in great shape, the CV-boot is torn, but no water is getting into the joint, <yada yada>. My advice is to not worry about any of those things, and continue driving the car to get the value you paid for." No charge for checking all that stuff. When the 2015 TDI went in for the "two or three day" smog fix, they gave me a brand new Alltrack for a loaner. When the parts weren't forthcoming, they said to keep the loaner. Had it almost a month, no problem.

Any how, the new dealer, said that it would be best to wait until the failure occurred again, because then they could for sure figure it out. I've put quite a few miles on it since my original post, and the problem has not duplicated. So, I'm thinking the very close lightning strike the night before the problem showed up may have caused a glitch in the electronics.