Originally posted by xr4ti:
For you CD4E atx experts out there,
Does anyone know exactly what triggers the flashing O/D light? I suspect it is the torque converter lock up slipping. Is this correct? Why does it not set a PCM code? I recently spent $2K on a tranny rebuild and I still get this error. The tranny shop says they will take care of it, but I really want to understand what is going on. How is it that they can essentially replace the tranny and I still get the same error? Anyone that can shed some light on this wouls be greatly appreciated.





It is my understanding that if the O/D light flashes, it represents an electrical malfuction with the transmission controls. Baiscally, it means that the PCM has detected that one of the sensors or the solenoid block is malfunctioning.

Understand that the whole OBD system works off of Inputs into the PCM (a component communicating with the PCM) and Outputs (the PCM communicating with a component). When something keeps that line of communication from taking place, it will set a code in memory, hince the MIL.

Now! With that said, I do not know of any striaght documention that explains what conditions have to be present for the O/D light to flash. I do know though, that if the light flashes, you are more then likely now working in a sort of "Limp Mode". For the transmission, this will basically mean that your TC will not lock and most of the time, line pressures will be regulated at a little higher rate. I also know, that if the O/D light flashes it doesn't always mean that there will be a code stored in memory. Most of the examples that i have dealt with, here on the boards, there was not a code set. The only way to retrieve that code, in this case, is to drive the car with a monitoring device that can take snapshot data from the PCM at the time a error occurs.

Again, this is what I understand from all the information that I have been able to gather. I will also state again, that information on this topic is pretty slim, so... But I hope it might help you out a little.

Phillip Jackson `98 Mystique LS 262K+ and counting... ATX rebuilt @ 151K "This storm has broken me, my only friend!" RIP Dime