Thread: Scanner can't connect to ABS.

I have a 99 GT. Obviously I have my ABS light on. I've replaced both front bearings/sensors because they needed to be replaced regardless. But light is still on. I've attempted to hook up two really nice high dollar scanners to read the ABS codes, but neither scanners can connect to the ABS module. However, both scanners connected fine to read the PCM. I've also sent my ABS module off to get repaired, but I was told its fine and isn't in need of repair. None of the wheel harnesses look really bad, but is the only thing I'm guessing atm since I can't get a scanner to connect to the ABS. Any suggestions? And anyway to diagnose the harnesses with a multimeter?

No codes because scanner can't connect to pull any codes.

But no codes from the PCM either.

These were shop scanners that DEFINITELY did ABS. Am fortunate and have friends who work for two different shops. Neither of the scanners could communicate with the ABS. Was looking at the wheel harnesses closer. The driver side has a different plug into the main harness than the passenger side. Both sides have the same plug into the sensor/bearing, but into the main harness they are different. Is this normal, or did someone add a different plug? It looks factory, but could have just been done really well too.

The fuses are fine. The scanners connect to the pcm fine, but not to the ABS.

Oh hell. You would have to ask me that. I have no clue off the top of my head. I believe one was a Snap On. The other, I don't even remember. I can go back and find out later this week. The one I don't remember belongs to the County's shop that services all of our county's fleet vehicles.

Also just added di-electric grease to all of the ABS connectors. Not only did it not work, my blower motor resistor decided to crap out as well. Talk about weird timing.

I went thru this hassle. Just b/c scanner is expensive or claims to read abs does not mean it will work on your make, model, yr. Save yourself hassle & go to gm dealer w/ tech II scanner & get ALL, including 'u' codes in writing.

If youre morally opposed to dlrs, go to gpona.com & create account to access service manual-it has wiring diagrams, pinouts, & testing procedures.

Good luck