The first step is to check the battery voltage using a VOM at the terminals with the car off. If it is below 12.5V it can lead to all sorts of electrical gremlins. TheU1040, P1571 and 1689 codes are related to the Electronic Brake Control Module (EBCM) with those I would check the engine grounds first. Use the search button and look for all the ground points. The P0135=0155 are Oxygen Sensor codes. The B0432 is the rear window defogger. IF the battery voltage is up to par then checking the engine grounds would be the next step, followed by clearing all the codes on the DIC (again use the search button if you do not non how to display them on the DIC) and relist the codes. When a U1040 code shows up it means there was an interruption of voltage to that module. After those are done run the codes run the codes and report back. If the battery does not read the 12.5+V you can try to recharge the battery and let it set over night before retesting.

 

Good information Gordy, these cars can be an electrical nightmare and I hope the OP can get it sorted.

 

No Comm could be the module(s) not getting power. Either bad ground or no +12v. My guess is bad contacts in the ignition switch. You can remove the switch and clean the contacts if needed. You would need to remove the knee bolster to get the switch out. I would first check battery voltage as someone else suggested. I would also check the grounding blocks under the hood and make sure they look good.
Here's a link for the service manual, it contains info for the electrical system. https://drive.google.com/open?id=0B1...l9xbGIzV3BtcjA

 

 

You have received good advice. Even though your have a new battery, make sure it is fully charged and it wouldn't hurt if you could have it load-tested. Lots of problems are created when the battery is not 100%.

I would start by addressing the loss of communication problems. These comunications take place through the Serial Data Bus, and it seems something is not allowing the normal data flow. Once the Serial Data Bus is corrupted all other devices that use it get affected.

This problem has been extensively documented by Bill Curlee and you can read more here. It is usually caused by bad contacts in a connector within the doors' rubber accordion.

The Serial Data Bus goes through the rubber accordion to the door control module. The female pins of the connector on that wire harness get deformed, causing bad contacts and loss of communication/corruption in the Serial Data Bus affecting all modules linked by it.



You can troubleshoot by opening the Star Connector 2 by the passenger's foot well, which isolates both Door Control Modules along with the Left Seat Control Module and, if commucations are restored to the other modules, then you have your culprit(s).

Check the connectors for deformed pins. If bad pins are found you would need to repair the connector (disconnect the battery first), fixing the female pins so they have a positive grip, or replace it. If you want to replace the connector take a look at this post for some ideas.

If connectors are fine, then the problem could be downstream the connectors up to the door control modules, or in the wiring/connector for the driver's seat up to the seat control module.


The Star Connector 2 is the one that has four wires. To perform this test you have to pop the top shorting strip off the top of that connector.

 

try to open your driver's door when you get those error's and see if the radio works. If it works the nthe problem is in the driver's side door