I was driving this morning listening to AM radio when it went silent, switched to another station and got nothing. Then radio power went out and the dash clock got dim. Engine started to stutter and the car stalled. I tried restarting it but nothing and the check engine light went on.

The tow truck jumped my battery and got it started again. The code I pulled out is 0804 which translate to "A/T control unit or circuit fault." So I went ahead and did the diagnostic trouble code for the automatic transaxle according to the Haynes Manual. What I got was 1 long blink, a medium pause, 11 short blinks with a short pause in between each one, then one long pause, and the whole thing repeats. What I don't understand is how to interpret this sequence with what's explained in the book, chapter 7 part B.

From my guesses the car some how lost/drain power from the battery since a jump started it. The tranny may have something to do with it but in what way I don't know. The check engine light is still on even though the car starts fine now but I don't know when the original problem will come back. Could someone give me any input based on what I've described and if you have the Haynes Manual explain to me how to read the AT diagnostic code? Many thanks!

 

Anyone?

 

Please read the "Sticky Thread" Important: ECU Diagnostic Trouble Codes. You will see that one of the possible causes of DTC 0804 is a weak or dead battery. You may have an electrical system problem and the Transmission Control Module is an innocent victim. Please resolve the electrical problem (battery, alternator, or both), reset the Engine Control Module, and drive the car normally. If the Check Engine Light returns, do another DTC readout and post the results on this thread.

 

I found the mentioned sticky thread after my second post and I'm hoping it's the battery. After a couple more searches I also found your explaination on how to read the TCM diagnostic code. Thank you!