My new blazer (2001 4x4 four door) came with an intermittant abs issue. Occasionally at low speed the abs system cuts in randomly and the ABS warning light is sometimes on. It had new front hubs about 18 months ago and I'm wondering if it could be related to this. Is this likely to be a sensor issue? If not how do I get any codes read as I'm in the UK so no GM dealers around here. Is it standard ODBII? Is there anything I can try/check first before handing it over to someone else who knows what they are doing?

 

Your basic ODBII reader doesn't do ABS, you need something more sophisticated like the dealer uses. It's a common problem (do a search). Common reasons are the wires are breaking down, I could see the split in the harness between where it hooks to the top of the A-frame and the sensor. The wires weren't routed properly (broken wires again) or you have a bit of rust between the sensor and the hub moving the sensor away and it's getting a weak signal. You can disconnect the connectors on the top of the frame and checking with an AC voltmeter you should see at least .25 volts from the sensor when you spin the wheel by hand. Chances are the weaker sensor is the problem one.

 

Can someone here tell (with certainty, not "I think so") which OBD2 scanner will "Display and Reset" ABS info and codes on a 1999 GMC Jimmy

--AND--

Which can "Turn on ABS Pump Motor" on the same vehicle.

Thanks

 

When my ABS light came on and off, it ended up being a faulty sensor wire that eventually got severed. AFAIK, you can't just replace the sensor since they are integrated into the hub assembly. You can unplug the sensor and clean it out then reinstall to see if that helps before replacing the entire hub assembly.

 

Yes you can remove & replace the sensors, they are held in with a small 6mm bolt, either hex socket ot torx - can't remember which without looking. They are a bit awkward to get to but it can be done.

 

One bolt per sensor. 5mm Allen Wrench (hex drive) not Torx. At least that's how the spare in my shop is.

 

Sorry about that, I was thinking about the bearing not being separate from the hub assembly, not the sensor.