ABS Light on - Diesel Forum

Patrolman · 12-01-2012, 08:16 PM

My ABS light is on intermittently. Vacuum pump is good,no vacuum leaks.
Power booster work fine. All positions work on heater and ac. Any ideals?

madpogue · 12-02-2012, 12:51 AM

Vacuum and power boost are unrelated to the ABS and won't turn the ABS light on. If the ABS light is on, it's more likely the ABS valve in the rear brake line, or the module or the like. Does the speedometer work normally?

chuckster57 · 12-02-2012, 01:00 AM

Check the fluid level in the brake master cylinder, and the float. Low brake fluid level will set the ABS light.

Patrolman · 12-02-2012, 09:28 AM

Brake fluid is OK, and the speedometer works with jumping.

chuckster57 · 12-02-2012, 09:43 AM

Next item to check is the VSS and its associated wiring. It's located on the top of the differential.

Patrolman · 12-02-2012, 05:41 PM

I have got to wait for the rain,snow and wind to stop.Last post had a mistake in it.
speedometer works OK, without jumping. Still think it may be the VSS?

chuckster57 · 12-02-2012, 05:50 PM

Does it seem to come on say after a hard turn, or like a banked on/off ramp? My fluid level was fine but I got on the highway on a fairly banked on ramp and was pretty deep into the throttle with 10,000 lbs of fiver hooked on trying to merge into traffic. Drove all the way to Yuba city with the light on. Stopped at a rest stop, shut the truck off and when I restarted, no light. When we got home, I experimented and pushed and held the float to the bottom, and when I turned the key to the run position my ABS light would come on.

Not saying that's your issue, but my float seemed to stick, and once I got it moving freely, haven't had that light again, been at least 2 years now.