2005 Envoy ABS Issue

[snowymountains]

I'm having an issue with my father in-laws 2005 4x4 Envoy.

The ABS light came on a while back and I just didn't have the time to look at it. A few weeks ago it started to pulsate every time you hit the brakes.

So finally got around to it last weekend. I have ScanXl and am unable to connect to the ABS system. I can connect to all other systems.

So I checked the usual ground under the drivers seat. That looked pretty good but I cleaned it up anyways. Didn't do anything.

So that it would stop pulsating until I figured out the problem I pulled the 60amp fuse. However, at higher speeds when you apply the brake it still pulsates. I thought by yanking the fuse that it wouldn't do this.

I am thinking the controller but thought I would seek opinions. I attempted to take off the controller but the darn torx screws are filled with crap and the clearance between the floor and controller is such that I can't get anything in there to loosen the ones closest to the frame. Looks like I'd have to take the whole assemble off.

Would love to hear anyones thoughts.

 

[Wooluf1952]

Welcome

In case you haven't heard:
http://gmtnation.com/forums/topic/218-welcome-to-gmtnationcom-heres-the-story/

Is the pulsating the same as when the ABS is working? With the fuse removed the only thing I can think of is a warped rotor.

 

[snowymountains]

Yes it's the same as when it is working. Very weird.

 

[JerryIrons]

That was my first thought too, warped rotor.

 

[djthumper]

If it is happening without the fuse in there is a good chance that you have a warped rotor up front. The front brakes take a lot of the power used for stopping.

 

[Tiggerr]

+3....rotor time

 

[snowymountains]

It was a warped rotor.

I replaced the ECBM (ABS controller) with a used one that was known to be good.

Still have an ABS light. I still cannot connect to the ABS system with my ProScan XL software.
I can connect to all other systems.

I tried issuing command via the terminal but nothing is returned. I went by this post on this forum.
http://gmtnation.com/forums/topic/4947-how-to-read-abstccmpcm-codes-using-a-terminal-obdii-interface/

Maybe its because the code examples are not relevant to a 2005 Envoy?

I have voltage and good grounds.
I continuity checked the wiring.

About ready to shoot it

 

[Mooseman]

I would suggest that you buy an ELM327 like this one and get Car Gauge Pro for Android for $5. It reads everything without any special commands or anything.

If the ABS is activating for no reason, a lot of times it's because of a faulty wheel sensor or hub. Check out this thread with a similar issue.
http://gmtnation.com/forums/topic/13336-tracing-a-bad-shorted-wire-or-water-short-from-sensor-connector-to-ecbm/