ABS light and trouble codes


bheston
11-16-2010, 08:02 AM
I just bought a 2005 Uplander, when I bought it the brake and ABS lights were both on. I quickly found a broken wire on the left front ABS sensor and repaired it. I have an OTC Genesis scan tool and I cleared all codes. As soon as I started driving again the ABS light came on. The brake light stayed off. I am getting these two codes now:
C0040 - Right front wheel speed circuit malfunction
C0041 - Right front wheel speed circuit range/performance

I have inspected the wiring and don't see any physical problems at the right front wheel. I can see ABS speed data with the Genesis tool, and I always register a speed on the right front wheel equal to the speed of the other wheels when moving. I have cleared the codes a couple times and one of these two codes keep coming back soon after I start moving.

What can I look for?
Do I just have an intermittent problem that I haven't caught watching the wheel speed in the ABS diagnostics?
I don't want to replace the wheel bearing/sensor if it isn't bad, any ideas how to troubleshoot this further?

TIA, this site is full of great information!

dorfboy
11-17-2010, 12:06 AM
It sounds to me that the wiring is bad. Usually the wiring goes bad and will need to be replaced. The wires are spiralled together and it will need to be done this way after the repair is made. It has something to do with the resistance in the wring and all of that.

bheston
11-17-2010, 08:15 AM
It sounds to me that the wiring is bad. Usually the wiring goes bad and will need to be replaced. The wires are spiralled together and it will need to be done this way after the repair is made. It has something to do with the resistance in the wring and all of that.

How much of the wiring should be replaced? I haven't traced it very far, is there a connection that can be unplugged up the line further and replace only the piece closest to the wheel, or are we looking at cut/splice the harness somewhere?

dorfboy
11-21-2010, 03:27 PM
On some of the chevy vehicles I work on, the abs/wheel speed sensors can be unplugged right at the top of the upper A-arm/control arm. The wheel hub is part of this system as well and can be easily replaced by removeing the tire, brake caliper and knocking back the axle shaft to loosen it from the wheel hub. I say this because a new hub will come with a new speed sensor and wire. But if you want to tackle the wiring I would just cut out about 6 to 8 inches of the wiring, starting at about an inch to inch and a half away from the plug at the wheel. Make sure you solder the wires together and use heat shrink to seal them

Add your comment to this topic!