CarFusebox

ABS light, Airbag light, Daytime running lights always ON Chevrolet BCM Issue sure sounds like a loss of communication between the control modules. the tough part, the system is like the old christmas tree lights. if one of the modules go down, it can pull down the hole data stream. same goes with the serial data line. what is really needed to help isolate this problem is a GM tech 2 scan tool. if there is no way to get your hands on one of these tools, the only other option you have is, check each control module power and grounds. to make sure the wiring is good. next step would be to check the serial data line for any opens or shorts. I have even seen a control module pull down the system. any one of the control modules could cause this. and they are all quite pricey.   just had a thought, I have seen ground G110, which is the ground for the abs and 4wd modules cause a problem. there is some ground wires mounted on the left frame rail, just below the drivers door. ma...

Chevrolet BODY CONTROL MODULE WIRING DIAGRAM Ok, the bcm is a real possibility. the bcm is kinda a central computer for all the control m modules to communicate with each other. the engine control module, abs module, 4wd module, air bag module and dash are on what is called serial data circuit. kinda works like a network of computers. there is a circuit called data line that connects all these modules together, so each control module can talk to each other. if there is a problem with one of the modules or the line itself, it can cause all of these problems. we can rule the ecm out because it runs. this problem can be very hard to check out. you will have to start with checking all the power and grounds to each control module. if all this checks ok, then the data line system will have to be checked for any problems. if all the wiring check ok, then a bcm would be the likely problem. here is a wiring diagram on the data line. The data link connector (DLC) allows a scan tool...