[sanz521]

First track day I did with my ZL1 1LE was perfect. No issues.

Today is my second time in this car, and during my first session the check engine light came on. Pulled off, and had a text from the onstar service saying I needed to service “engine and transmission system in next 7 days”.

Talked to onstar and they saw no error codes on their end. So went in for another session to see how it was and everything felt fine for a bit until it seemed to have cut the throttle. Engine would go up in rpms but slowly.

Pulled off and again onstar said no issues. Went and got gas, as I was a little over half a tank. Driving back from the gas pump, the light turned off on its own.

With that I went in for another session, did 4-5 laps car perfect, then light came on again and again cut power.

Any ideas what’s going on? I’m thinking with the high G turns, the car maybe thinking it’s low on fuel. Happened previously on a Porsche

[sanz521]

Update: refueled even though I was at 3/4 and this time light didn’t go off. Onstar diagnostics still not showing any errors though

[ZLRob]

Oh boy.. I hope you don't have issues at the harness running underneath the engine by the crank pulley.

[sanz521]

Originally Posted by ZLRob

Oh boy.. I hope you don't have issues at the harness running underneath the engine by the crank pulley.

What would this cause or how could I check for it?

I ask because by the time I packed my stuff up at the track, and hung around to watch some friends, I got back in the car and the light was off again. So if I take it to the dealer (since it’s still under warranty) they’re not gonna pull any codes.

[Vigilante375]

Sounds like you're right about the low fuel thing. The fuel pickup is on 1 side but I don't remember which side so it'll think it's low of fuel.

[ZLRob]

Originally Posted by sanz521

What would this cause or how could I check for it?

I ask because by the time I packed my stuff up at the track, and hung around to watch some friends, I got back in the car and the light was off again. So if I take it to the dealer (since it’s still under warranty) they’re not gonna pull any codes.

I can't find the thread for it, but I wouldn't worry about it if it was a fuel issue. Especially considering you were low of fuel and pulling high G's while you were low.

[sanz521]

Update 3: was able to get my hands on a OBD scanner and even though the light was off, the code was still there.

P0325: knock sensor

Thinking might be bad gas? Still think I’m just gonna take it to the dealer and have them deal with it since it’s under warranty still

[SATINSTEEL1LE]

Originally Posted by sanz521

Update 3: was able to get my hands on a OBD scanner and even though the light was off, the code was still there.

P0325: knock sensor

Thinking might be bad gas? Still think I’m just gonna take it to the dealer and have them deal with it since it’s under warranty still

Probably still low side fuel pressure drop enough to effect the high side and making the car run lean. Then it sees excessive knock and throws the code.

[sanz521]

Anyone know where the knock sensor is located? Wanna see if it’s visibly lose just to tule rule that stupidity out

[Vigilante375]

Originally Posted by sanz521

Update 3: was able to get my hands on a OBD scanner and even though the light was off, the code was still there.

P0325: knock sensor

Thinking might be bad gas? Still think I’m just gonna take it to the dealer and have them deal with it since it’s under warranty still

My 1 and only experience with bad gas was in my old 2013 Tundra. The truck took about 3 or 4 tries to crank up.

Doubt it's bad had but the low side pump "starving" for fuel.

[Stephen12ZL1]

knock sensor code is likely a bad knock sensor...cheap part and easy to replace. Dealer will swap out the sensor and clear the code.

[ZLRob]

My advice given what's going on?

Get an HP Tuners MPVI 2 module and setup channels to monitor what the heck is going on. If you are knocking and it's knocking enough the computer will definitely show that in a catalog and you can rule bad gas as the culprit to your issue.

These cars are very dependent on using high quality fuel. If you use anything less you'll run into issues potentially triggering a knock sensor code.

[Evansa22]

Hope this helps, starter doesn't need to come off, just the heat shield for it, which is 3 10mm bolts I believe. Might be able to just move the wires up and down and see if it moves. If its under warranty I'd have them deal with it though, even with how incompent some of them may be.

[JTS]

Don't tell them you were at Track days, per my service advisor, and no stickers on the car. You were driving and the Check engine light came on period.