95 C2500 Egr And Abs

Boyzbad · June 14, 2011

Ok I give up! I am completely stumped. Truck is a 1995 C2500 HD 7.4 4L80 and the brakes are vac. abs with 3 sensors.

1. The code I'm getting is #32. Light stays on all the time know while it used to come on and go out. I have noticed a slight reduction in mpg. I have tested the egr and it checks out ok when performing the diagnostics. However I have not replaced the control module which is the ecm? Also do I need an updated prom chip or use the one from the old computer?

2. The abs light comes on everytime you restart the engine and move 5 feet. All the sensors are ok. I did run to a friends shop and the scan tool was reading -700mph on all the sensors. It also says there are no codes. Is there a separate control module for the abs besides the large deal under the hood on the left fenderwell? If there is where is it?

Any help would be great.

Gary

GMstrong · June 14, 2011

Get a voltage light and check out the power connector,code 32 is bad circuit to the EGR.check brake fluid,Yes there is a EBCM.I belive its on the passenger side not 100%.It can be done by you but it is in a very tight place. Small torx head screws that are facing the floor boards to remove this module.

Boyzbad · June 15, 2011

Get a voltage light and check out the power connector,code 32 is bad circuit to the EGR.check brake fluid,Yes there is a EBCM.I belive its on the passenger side not 100%.It can be done by you but it is in a very tight place. Small torx head screws that are facing the floor boards to remove this module.

Ok there are 4 wires going into the egr. I have 12v on one with key off and with key on 2 12v. Black wire is ground all times. The one that is off when key off checks out as ground. With key on if you unplug and plug the egr in you can hear it open and close. Brake fluid is up. I've gone over all wiring and checked fuses. Is the relay built in for the abs motor? It has 2 connectors going into it (both blk/red) and one is hot while other is not. Is there a way to test the motor? There is also a sensor on the side where the 5 brake lines are on the manifold, how to test that? I also pulled the ebcm but it looks ok, nothing on the circut board looks bad.