Hi,
I have a 2000 Park Avenue base that has a weird intermittent electrical problem.

The first sign of the problem is that the doors don't unlock with the remote.Then the windows don't work using any of the switches. While driving, if you turn the heated seat on and then off after a few minutes the airbag and security lights will illuminate, the orange light that indicates what gear the car is in will turn off, all of the values under gage on the DIC will turn to question marks, the fuel info on the dic will turn to dashes, and sometimes the TRAC OFF light will turn on and the gear indicator will reappear.

Turning the car off and then back on will make the airbag and security lights go off but you can get them to turn on again by turning the heated seat on then off.

I read on alldata that the DIC will turn to question marks and dashes when the DIC loses contact with the PCM. That leads me to believe it is a problem with the class II serial data link. Is there a way to test that?

Thanks

Sounds like a ground problem. Start checking for corrosion. You will need to locate the ground points on your car. Sorry but I'm not sure where they are located for your year. But I think they are under the dash along the outside wall. Remove the kick guard and you should find them.

I checked the grounding points the other day and they didn't have any corrosion on or around them. Could it be storing any codes without turning on the service engine soon light? I took it to autozone and they said they could only pull codes if the light was on.

I found instructions on how to test the serial data line here: http://ocw.weber.edu/automotive-tech...data-circuitry

I tried that a my multimeter was reading around 18k ohms. I tried unplugging the driver door module and the PCM to get the reading to change but I'm not sure what other modules to unplug.

Yes, there are codes that wont trip a light. But those readers are unlikely to read chaise codes. You would need something a bit more advanced, like a tech2, and generally only dealerships hove those.

I don't recall anyone ever testing the data line. If it connects to a code reader, then it should be working correctly.

So is there anything else I can try other than taking it to a dealer?

Nothing that comes to mind. Could be the body control module. But this is not really my area. Sawgunner might have some in site on this.

I have a similar intermittent problem with my 2000 Park av