This is a long story. It started when I blew my transmission and had to pay someone to fix it. About a week after I got it back, the ABS light came on. Now, I NEVER EVER have someone else work on my car, but this time I was out of town and had too. I'm already sure they messed it up by pinching a wire or breaking a sensor, etc. Anyway, I hooked it up to a scanner which claimed driver's side front malfunction. Figured I would replace the sensor and clear the codes to eliminate it as a possibility. The scanner I used was @!#$ and I'm not sure if it actually cleared the codes or not. That being said, the light is still on. If the sensor was bad and replaced with a good one, would the light eventually go out without clearing the codes? I have no experience with abs systems unfortunately.
If there is a short or a broken wire somewhere, whats the best way to diagnose? I know it probably isn't 12v going to the sensor, so would a test light illuminate at the plug even if there was power going to it? I don't feel like buying a multimeter but I guess I need too now. When I had it apart I checked the wires from the sensor plug up to where it goes above the fender, no problems there. Where do more knowledgeable minds suggest I start looking? All suggestions accepted.
Edit: 2005 LS Sport Cavalier
Edited 1 time(s). Last edited Tuesday, November 27, 2012 8:32 AM
"In Oldskool we trust"
Usually they will clear themselves but im not positive. What code did you have by chance? Usually testing is doing a resistance test on the sensor. Then setting the multimeter to AC voltage and spin the wheel to make sure it is producing a voltage. most common problems for cavaliers are bad wheel speed sensors or breaks in the wire harness.
Thanks for the info. So if the wiring was good, what readings would I see at the plug?
"In Oldskool we trust"
Update,
Wheel sensor is giving voltage but with the key on I'm getting no readings from the plug. Guess this means I'll be tearing the harness apart...
"In Oldskool we trust"
I believe its either autozone or gm that you can buy a connector and harness. the connector should not have voltage with they key on as it doesnt need to supply any to the wheel speed sensor. The wheel speed sensor reads off a trigger wheel and produce ac voltage when spun. what your looking for is excessive resistance or a break in a wire on the harness
This whole situation really chaps my !@#. The harness you speak of, is this just a pigtail to splice in somewhere or something else?
"In Oldskool we trust"
Actually, what I would suspect is a wire shorted to ground. Unplug the abs sensor, and the plug at the ebcm, and check both wires one at a time for resistance to ground. If you have something besides ol, it's shorted. If you get ol, check resistance of the wires individually from end to end(abs connector to ebcm connector). You really only want up to 2 ohms here, the lower the better(0 is optimal). If you get good readings on this test, then lastly, check each wire while still disconnected, for a short to power. With key off, check resistance to b+ terminal on the battery. These are all wiring checks that you could do. If resistance of the sensor is good, and all these tests are good, it's the ebcm or the reluctor ring on the axle.
Also, gm has a bulletin out for front abs codes and eater intrusion. In the bulletin, they state that by looking at the connector you can't tell that water ws present, but if you strip back some of the wires, they will look either black or green. If this is the case, they want the sensor ant the pigtail replaced.
Let us know what you find!
Your helpful gm tech,
Dave
Wow GREAT info! Thanks man.
"In Oldskool we trust"
Glad to help. Let us know how you make out with it
