Code Errors for 2004 Cadillac Deville
I’ve asked for help on this in the past but wasn’t able to get any help. I have this strange light/electrical problem. My interior lights won’t turn on by themselves when it’s dark. I can only manually turn on the map lights with each button. They don’t turn on when I manually open the doors or when I unlock my doors with the key fob and they don’t turn on when I move the interior dimming **** all the way over. That should turn the lights on. Also, the lights on the bottom of the door (puddle lights) don’t ever turn on. I decided to run the on board diagnostics and I get the following errors. Not quite sure if it will solve my problems but they are valid codes so I want to see what they mean.
Here are the codes that I’m getting. Theses seem to be Network Codes from what I’ve read.
U1000 – Class 2 Communication Malfunction
U1016 – Loss Of Class 2 Communication with VCM or Loss Of Communication with PCM
U1065 – Loss Of communications with IPM
U1176 – Loss Of RFA communications

My confusion is that while running the diagnostics, it comes up with the following along with a bunch NO CODE. For you guys that have run this, you know that it checks each "system" and either displays NO CODE or it will display an error code. I didn’t write them all down but these stuck out to me so I wrote them down.
NO RFA CODE
NO IPM CODE
What I don’t understand is that I get a U1065 error that is supposed to be an IPM error. Why would the Diagnostics show NO errors for that code? It specifically comes up NO IMP CODE. It makes no sense. Please help if you can. Thanks.

 

I ended up resetting all the codes this moring after I read the codes amd posted. I left work and drove home like I normally do. I drive 47 miles of highway speeds, stop and go highway driving and a little city in town were I work then in town were I live. I checked the codes when I got home and the only one still there is the "Current U1000". I have to check it again in a few days to see if anything else comes back. What does the Current U1000 mean?

 

Its a communication code, modules not talking or one is sending data that confuses the others. How good are you with electrical concerns? Do you you have access to alldata or fsm disc and a dvom? This may not be simple. Hopefully you have checked fuse and relay already.

 

I work with electronics everyday. I'm a Electronics/Telecom tech. I do have a Digital Voltmeter but I don't have a FSM or alldata. I was looking into getting a servicemanual once but never got it. A little too pricey. Now are you thinking that may solve my lighting problem or is that just an error when the communications is lost that may not cause a noticeable problem? Thanks for the reply. It's tough to get replies or answers sometimes.

 

Grounds are normally a good place to start, do have anything to tell you where to look? You have checked fuse and relay right?

 

I checked all the fuses and there good. I don't have anything that may help me trouble shoot.I may have to eventually bite the bullet and get the FSM. It'sjust so expensive.

 

I need to know if you have rpo V4U OR B9Q It would on label on spare tire cover. FSM may seem pricey but dealers and repair shop labor rates at as low as 60 to over 100 per hour; is good information that expensive?

 

I agreethat the info is worth the price. I just had some big expensence this past month. I hope to get one after the holidays. Hopefully. I'll check the info you ask me about and I'll post it later today. What does this mean, V4u or B9Q?