The curious case of the disappearing check engine light

[Murray20c8]

It's beginning to bug me.
2 heat cycles and it's gone.
Sometimes 4
Last time it happened I managed to scan the car.
p0308 cylinder 8 misfire
p0700 DCT
p287c unknown
p1967
Hopefully if I ever get the DCT patch installed it will cure it.

 

[JoeyBats]

It's beginning to bug me.
2 heat cycles and it's gone.
Sometimes 4
Last time it happened I managed to scan the car.
p0308 cylinder 8 misfire
p0700 DCT
p287c unknown
p1967
Hopefully if I ever get the DCT patch installed it will cure it.

Murray, hopefully not the start of those dreaded electronic gremlins that cannot be recreated when you take it to the dealer.

 

[Thom]

A system update has not occurred for me since I got the car. My system notes that it is a July 2020 date. Just realized my car's wifi was not connected to my home wifi. Set that straight this morning so it will be interesting to see if any updates occur over the next day or so.

 

[Murray20c8]

A system update has not occurred for me since I got the car. My system notes that it is a July 2020 date. Just realized my car's wifi was not connected to my home wifi. Set that straight this morning so it will be interesting to see if any updates occur over the next day or so.

Updates are done via cellular, not wifi. Wifi is for apps like myChevrolet

 

[Gilles27]

Murray when you get cylinder 8 misfire, does it idle rough like having a bad injector?

 

[Thom]

Updates are done via cellular, not wifi. Wifi is for apps like myChevrolet

Does that still occur even if my trial OnStar has expired and I have not bought into the plan?

 

[Murray20c8]

Does that still occur even if my trial OnStar has expired and I have not bought into the plan?

Yup. It uses OnStar tech I bet, but OTA is cellular

 

[JR410]

It's beginning to bug me.
2 heat cycles and it's gone.
Sometimes 4
Last time it happened I managed to scan the car.
p0308 cylinder 8 misfire
p0700 DCT
p287c unknown
p1967
Hopefully if I ever get the DCT patch installed it will cure it.

That sucks, good luck.

 

[Murray20c8]

Murray when you get cylinder 8 misfire, does it idle rough like having a bad injector?

I notice nothing at all except the CEL.
The only noticeable difference is it won't remote start with the CEL on.

 

[Sparro]

CEL codes should be stored in its memory. So even if you can't recreate the symptoms when you bring the car to the dealer, the old codes should still be there in stored memory.

 

[Murray20c8]

CEL codes should be stored in its memory. So even if you can't recreate the symptoms when you bring the car to the dealer, the old codes should still be there in stored memory.

I thought that, but the dealer told me they weren't. Perhaps some are and others aren't??
My code reader likely only reads current codes. Not sure why the dealer didn't want to investigate further. Unless he didn't want a tech chasing a ghost, but warranty work is paid for by GM isn't it?

 

[Sparro]

I thought that, but the dealer told me they weren't. Perhaps some are and others aren't??
My code reader likely only reads current codes. Not sure why the dealer didn't want to investigate further. Unless he didn't want a tech chasing a ghost, but warranty work is paid for by GM isn't it?

When I brought my Jeep into Williamson's for service they told me the codes were stored in memory and were able to see the fault code even though the CEL was off when I went in. I assume this holds true for all modern cars. Even an independent mechanic friend told me the same thing when I comes to CELs.

 

[Murray20c8]

When I brought my Jeep into Williamson's for service they told me the codes were stored in memory and were able to see the fault code even though the CEL was off when I went in. I assume this holds true for all modern cars. Even an independent mechanic friend told me the same thing when I comes to CELs.

Thanks. I'll make an appointment then. I must have misunderstood him. Or he was being an .... lol

 

[Sparro]

Thanks. I'll make an appointment then. I must have misunderstood him. Or he was being an .... lol

Wouldn't surprise me. Most people are lazy and will do the minimum required of them.