Any of you gotten this code before? My 97 GXE (auto) starts and idles fine, but as soon as i put it in drive or reverse it will kill. This only happens after it has been sitting long enough for the temp gauge to show cold. It starts drives fine when it's warm. It's been a little colder here lately, so I thought it was weather related, but this morning was pretty warm and it still did it, so I pulled codes. Got 0504: Automatic Transmission Control Unit Signal to ECU. The stickies define 0504 as:

Diagnostic Trouble Code 0504 points to a problem with the Automatic Transmission Communications line. Pulse signals are exchanged between the Engine Control Module and the Transmission Control Module to assure smooth shifting during hard acceleration or deceleration.

This malfunction is detected when the ECM continuously receives an incorrect voltage from the TCM. Possible causes include...
- Harness or connectors (The communications line circuit between the ECM and the TCM is open or shorted.)
- TCM
- Discharged or faulty battery

I tested the charging system before winter, and everything is fine.. I put a new battery in as well about a year ago, so that rules battery problems out.

How can I figure out wtf is going on? I have no idea where to start. Am I going to have to bite the bullet and go to the dealer

Thanks in advance...

 

bump for the day shift

 

I have. In my case 0504 had nothing to with weather. It always came with 0104 (Vehicle Speed Sensor). When I fixed 0104 issue, 0504 also disappeared. It has never come back since then. Seems to me that yours was caused by some other reason. Electrical diagrams may help if you try to fix it yourself.

 

thanks hasei. i have never gotten 0104. i already looked through my trusty haynes manual for 0504, but didn't find much help. was your 0104 a ghost code, or did it throw a cel? the 0504 is a ghost code, no cel to tip me off. i don't even know what sensor to test or anything.. i'm at a loss right now. i called the dealer today and (of course) they told me they couldn't do anything without looking at the car.

 

It threw a CEL. Did you run a diagnostic on AT in FAQ? If you haven't, you might be able to have a better idea of exactly what sensor or circuit sends TCM an incorrect signal.