Thread: Bad wiring? Or bad module?

05 Comp G

Been driving for a couple months with ABS, Traction, and BRAKE warning lights all on. Started as just ABS and Traction intermittently coming on (shutting off when I restarted the car) then when when they were solid and not ever turning off the BRAKE light joined.
Finally made friends with someone that has a computer to read brake codes and it came up Front Right Wheel speed sensor.
Replaced the hub on that wheel but the lights are still sticking around.
Shot some WD-40 onto the harness to try to clean it out and although I don't totally understand a multimeter, I was about to get some sort of reading through the harness while the ignition key was ON.
Finally realized that there were actually 2 codes that came up on my buddy's scanner:
C0121 Valve Relay Circuit Malfunction
C0040 Right Front Wheel Speed Sensor Circuit Malfunction

Tomorrow I'm gonna rip a harness from the Pick N Pull just to be certain it's not just a bad connection, but that C0121 code has me worried, am I really gonna have to drop ~$400 on a new module?

No. I have the same car and Matt Malory at cheapabs.com repaired mine. He's on ebay. I don't remember the name, sry.

It isn't something I wanted to attempt myself, even tho fb kept saying it was "easy." Instead of risking $400 in damage done with no help at all, which didn't seem like a very good option, I sent it to him for about $125.

I never could totally remember the code the shop pulled. I believe it was like 0500, but idk.

Hardest part is taking the thing out. I didn't drive it with the module off, even though it says you can. Matt was actually on vacation when I sent mine in. Turnaround was still within about a week.

I just clicked over, and Matt is closed until July.

Personally, I'd search ebay for the same service with good reviews. You should be able to find someone to repair it.

Thanks!
In my research I found cheapabs.com, I assume that's the guy you're talking about? There's an auto shop that specializes in electronics in my town, I might swing by and see what they can do. Gonna have to wait till payday tho...

Just wondering, I looked it up on gmpartsdirect and it says that the module w/traction control AND active brake control (WS6 & JL4) is a discontinued part and googling the part number I couldn't find it available anywhere. But I saw a thread somewhere saying they used a gxp module and it worked. What's the deal there? Is there a difference? They are different part numbers.

Shop in town says no one here rebuilds modules. Anyone suggest a guy? Don't feel like waiting till July.
I'll take the module off and see if cleaning it some doesn't help.

Replaced the harness... SOB lights are still on. Gonna have to get the module rebuilt.

I would recommend getting new harnesses, they are not expensive. I had my module rebuilt but I also swapped out the old harnesses for new ones. With electrical I usually just replace vs. getting something used. But in the case of the ABS module, yeah wait for him. He fixed mine years ago and its held up ever since.