Code 42 after battery disconnect and reconnect

[TR Custom Parts]

Disconnected the ground wire from the battery since I was going to be working around the starter area and didn't want to be doing any surprise arc welding if I hit a terminal with a wrench. This was on my own GN with 39,000. Done with the work I was doing and reconnected the battery. Start the car up and get a Code 42 and the car was idling weird, different exhaust note, etc. Have read all the threads on Code 42 and a lot of different opinions on what it is. Anyway, shut the car off and restarted and the code was gone and car was running fine again. Hopefully was just a fluke deal from reconnecting the battery.

I have on occasion get a random stall out of the blue but car always would restart and never set a code. Have never figured that out and has been going on for years. No warning that it is coming, just shuts off. Everything is cleanly connected, no corrosion on anything. Running a translator plus with Z06 MAF sensor. Caspers ground relocation kit. Really need to capture this with the PL recording.

 

[rodruckus]

I have my own code 42 story to add. It won't help, but it'll further demonstrate just how mysterious and elusive 42 can be. This past winter I was doggin a m3 on the fwy, I'm wot and pullin hard on it when suddenly I got the loudest, most garbagey exhaust note I've ever heard a TR produce. The volume of it was well beyond that of an open dump.

I immediately lifted and dove off the next exit. When the light turns green and I try to go, I find my gas pedal is now rock hard and literally frozen. I had to mash the shit outta the pedal just to get it to barely move. My car is now accelerating like an old vw and the exhaust note is still super loud. Luckily, I was just a couple of miles from home.

Once I got home and looked up the code, it left me confused. Where the hell do I even begin looking for the problem. I decided to just begin with disconnecting the battery. I disconnected the battery, waited a few minutes, reconnected it, and started the car back up.

Much to my relief, my exhaust note and gas pedal went back to normal. Next, I took my car back out, and everything was fine. Now almost a year later, and it's like this was just a bad dream. The louder exhaust note does seem to be a common occurrence when 42 gets spit, but I'm curious if anyone else has ever experienced the hardening, almost freezing of the gas pedal?

 

[RmvBfrFlght]

The reason the exhaust note changes when code 42 is active is that there isn't any spark advance. It sits at 10* BTDC until the ECM is reset (key-off for about 5 seconds).

Mark, regarding the engine shutting off, check the C437 connector. It is behind the dash, passenger side, has foam wrapped around it. Can usually access it by dropping the glove-box down. The PNK/BLK wire in position F is IGN+ switched power to the ECM.

RemoveBeforeFlight

 

[TurboTnZ06]

Random stall? Check the power and ground cables under the header, make sure they aren't loose and burned through the insulation.

 

[GNRick]

The reason the exhaust note changes when code 42 is active is that there isn't any spark advance. It sits at 10* BTDC until the ECM is reset (key-off for about 5 seconds).

Mark, regarding the engine shutting off, check the C437 connector. It is behind the dash, passenger side, has foam wrapped around it. Can usually access it by dropping the glove-box down. The PNK/BLK wire in position F is IGN+ switched power to the ECM.

RemoveBeforeFlight

What would you check with the pink/black wire? Wiggle it with car running? My car died recently while turning left in the middle of a large intersection. Shifted to neutral and it started right up. Ran fine the remainder of the 700 mile trip.There were no bumps or pot holes that could have jiggled that wire. I think I had the ac on if that matters. Didn't have a chance to look at fuel pressure gauge but the pump is new as is the Racetronix hanger wire.

 

[TurboBuRick]

Could be a problem with the translator plus. Are you using the timing feature?

 

[RmvBfrFlght]

What would you check with the pink/black wire? Wiggle it with car running? My car died recently while turning left in the middle of a large intersection. Shifted to neutral and it started right up. Ran fine the remainder of the 700 mile trip.There were no bumps or pot holes that could have jiggled that wire. I think I had the ac on if that matters. Didn't have a chance to look at fuel pressure gauge but the pump is new as is the Racetronix hanger wire.

I would first physically look at the wires where they are crimped to the terminals. A slight tug on the wire(s) too. Then the wiggle test with the engine running. Having the engine cut out while turning is one symptom that this wire is compromised.

Note that this connector is for the ECM/EFI to chassis harness connection. So a lot of other stuff goes through it (TCC, ALDL, boost gauge, and so on).

RemoveBeforeFlight

 

[ScottyG]

This prob don't help but when I had a code 42 I switched out my chip and all the codes went away! I had like 8 codes like 33 35 54 55 if I remember . I just change the chip out and all the codes went away

 

[TR Custom Parts]

Could be a problem with the translator plus. Are you using the timing feature?

Yes, wired but never changed adjustment.