ABC Light and Speed Sensor Code

[Marshall2002]

I have a 2002 Denali with an ABS light that come on a few seconds after starting the engine. The code is right front speed sensor. I have replaced the sensor but still have the light. Sometimes at low speed the light will go off, and I can feel the ABS pulsing in the pedal. Given the light comes on at startup before the wheel moves, then it seems to me that something in the self test is failing, but I'm no expert. I tried to get a reading from the sensor with a multimeter, but since its AWD, I cant spin the hub even when in neutral. Any ideas?

 

[Doubeleive]

sounds like the senor you replaced is bad out of the box or the connection isn't good, I have had bad ones right out of the box before. try swapping the front left/right and see if the code follows the sensor or not.

 

[SnowDrifter]

Isn't there a tsb on these about the wheel speed sensor wiring?

 

[Marshall2002]

So just an update, the aggravation continues. Since the old girl has 290k, I decided to replace both front wheel bearing hub assemblies (speed sensors included) with new Moogs. Needless to say Im unhappy the abs light still comes on immediately after startup, but I still consider it money well spent on the bearings. I'm not sure what to try next. Maybe I just need to get used to the light.

 

[mattbta]

Likely need a new abs module (ebcm) or send yours off for repair. There's some youtubes on it.

 

[Marshall2002]

Likely need a new abs module (ebcm) or send yours off for repair. There's some youtubes on it.

Yeah...already had it rebuilt.

 

[Doubeleive]

Yeah...already had it rebuilt.

what is the code when the abs light is on? I had one rebuilt also which did not fix the problem the module was still bad, I ended up grabbing another one out of the junkyard (which was also bad) cracked it open and took it to a local tv/electronics repair shop and had the guy reflow all the connectors, sealed it back up and it worked perfect.
the code will define if the problem is the abs module or if it is still a wheel sensor.
you have to scan it while the abs light is on because if the module is bad it does not save the code and just goes away until it comes on again.

 

[Marshall2002]

what is the code when the abs light is on? I had one rebuilt also which did not fix the problem the module was still bad, I ended up grabbing another one out of the junkyard (which was also bad) cracked it open and took it to a local tv/electronics repair shop and had the guy reflow all the connectors, sealed it back up and it worked perfect.
the code will define if the problem is the abs module or if it is still a wheel sensor.
you have to scan it while the abs light is on because if the module is bad it does not save the code and just goes away until it comes on again.

I forget the number, but it was "Right Front Speed Sensor". When I first started this fiasco, I had both the abs and brake light with 2 codes. The speed sensor and The second was ebcm fault. That is why I sent it off for rebuild. When I reinstalled the brake light went off, and the second code was gone. I still have the abs light speed sensor code.

 

[Doubeleive]

I forget the number, but it was "Right Front Speed Sensor". When I first started this fiasco, I had both the abs and brake light with 2 codes. The speed sensor and The second was ebcm fault. That is why I sent it off for rebuild. When I reinstalled the brake light went off, and the second code was gone. I still have the abs light speed sensor code.

did you try swapping the front left/right sensors?

 

[Marshall2002]

I have replaced them both.