ABS light

**ct9a** · 10-16-2008, 06:51 PM

'94 Suburban 1500 ABS light comes on after the truck starts rolling within the first 10'. It turns off every time I cycle the ignition.

Is there anyway that I can pull the codes for this myself (like I can pull the engine trouble codes)? Or do I need to have someone with a scanner do it?

**moogvo** · 10-16-2008, 10:47 PM

1994 is pre-OBDII. You should be able to short the pins on the diagnostic connector under the dash to see what codes it pulls. If you look at the connector, you will see that there are several pins together, and then on the opposite corner, there are two lonely pins... short those with a paper clip or something similar.

Then turn the key on to the run position, but do not start the truck. you will see that your Check Engine light will start flashing. What it is doing is showing you 2 digit codes. The first time it will cycle through the number "12" 3 times to show you that it is working. (The light will flash once for the first digit (1), then pause then flash twice (2 for the second digit). So, for example, if after it shows you "12" 3 times, it goes "Flash flash flash (PAUSE) Flash flash flash flash) then it is telling you the code is "34" Get it? Good.

Now... I don't know that the OBD system in that vehicle will give you the codes for your ABS system... some of the older OBD systems will only give you engine codes.

WARNING!!! DO NOT ATTEMPT THIS PROCEDURE ON ANYTHING MANUFACTURED FROM 1995-PRESENT!!! YOU CANNOT READ THE CODES THIS WAY AND YOU WILL FUBAR YOUR COMPUTER!!!

**dmacatantan** · 02-23-2009, 08:00 PM

My ABS light come on at 15 mph speeding up and goes off 15 mph slowing down. ever heard of that?

**ct9a** · 02-23-2009, 11:48 PM

Never heard of that problem. I would double check to make sure that the reservoir is filled and then take it to have the codes read.

**BillBoost37** · 02-24-2009, 08:09 PM

Many times the speed appears to help the WSS to show it's faulty. One possible way to help figure out which WSS it is w/o having a scanner capable is to pull the connectors at each wheel and use the multimeter on the ohm setting (hopefully it's autoranging). Read all four WSS's and look for inconsistencies. If one is way out of wack, there is a good chance that's your issue.

**zachh1020** · 02-25-2009, 10:36 AM

I'm having a similar problem with my ABS. It comes on when I hit bumps and sometimes when I brake. Both WSS have been replaced. The rotors have been replaced too so there is no chance of it being a warped rotor. Any Ideas?

Z

**ct9a** · 02-25-2009, 11:39 AM

Have you checked for breaks in the wire insulation? I'd start there.

**zachh1020** · 02-25-2009, 07:39 PM

Both sensors/wires have been replaced.

**jchambers849** · 02-26-2009, 05:25 PM

My ABS problems were traced back to the ABS controller module under the hood... a new module later (and all new brake lines due to the increased pressure blowing every rusted line in the truck) and the light went off. Luckly, it all happened under my warrenty, which was a measly 30 day / 1000 miles long.

Do you hear the ABS motor at strange times or ever lose brake pressure when taking corners?

**zachh1020** · 02-27-2009, 05:05 PM

Originally Posted by jchambers849

My ABS problems were traced back to the ABS controller module under the hood... a new module later (and all new brake lines due to the increased pressure blowing every rusted line in the truck) and the light went off. Luckly, it all happened under my warrenty, which was a measly 30 day / 1000 miles long.

Do you hear the ABS motor at strange times or ever lose brake pressure when taking corners?

Yes. Sometimes it activates when I brake and sometimes the light just comes on and goes off while I'm on the highway. If it hit a bump the light will come on. Last night when I pulled into my driveway I hit my garage door because my ABS activated. Dented the hell out of it and knocked the lower garage door panel loose.