Engine/Transmission (1998.5 - 2002) ABS and Brake light on

[hpyman123]

Was driving yesterday and the ABS and Brake lights came on and stayed on. I shut down while rolling, restarted and they went away only to come back next time I started the truck. Replaced the Rear ABS speed sensor with no luck. Scanned the computer with my Modis scanner and it says there are no ABS codes. My understanding of the ABS light is that there is a fault in the ABS system unrelated to hydraulics. I've checked fuses inside and under the hood and looked at the wiring under the hood. At this point I'm scratching my head. Anyone out there give me a direction to go?

 

[Road Dog]

Not many scanners can read the extra modules like ABS. If the lights are on then there are codes. The first thing is check the fluid. Too low (even above MIN) can trip the light. You didn't say if you have rear wheel ABS (1 sensor on rear diff) or four wheel ABS (3 sensors). If the rear diff sensor isn't working then the speedo will not work or will be erratic.

 

[hpyman123]

All I have is RWAL. My scanner is a Snapon Modis scanner. There is a category for ABS on the screen and it askd for 4WAL or RWAL. I check RWAL and it says there are no codes. I would hope that since it's on the scanner it would work but it wouldn't be the first time it wasn't right.

 

[hpyman123]

I checked the fluid and it was low. Filled it up but lights are still on. I haven't driven it yet. Is there anything you have to do to reset it?

 

[Road Dog]

If that's the problem it'll turn after you drive it.

 

[HSpiering]

Is that a drum on the rear? Had that problem and it tuned out to be the need to adjust back drums. I think it was not going in revers hard enough to make them self adjust. NOt sure what on 01 has.

 

[hpyman123]

Yes it has drums on the back. If the fluid level doesn't fix it I'll check them next. They were just changed a few thousand miles ago but you never know.

 

[hpyman123]

Well after topping off fluid and driving the lights are still on. Will start by checking adjustment on rear brakes. Any more ideas?

 

[DavidC]

Try unplugging your hitch on the back of the receptacle. Mine did that one time so I unplugged it and took it for a drive. Result was no lights, I packed it with di-electric grease and no more problems. Worth a try and does not cost anything. Does your speedo work ok ?

Dave

 

[VolsFan]

on my old 99 auto w/ drums, the abs came on and the engine idled erratically, briefly one day. At that time I had a superchips programmer on it. I unplugged it and all the symptoms went away and never returned for a good 50k and I assume its running well for the owner of it now w/ over 200k. Cant explain it, but I never hooked that thing back up, only to check codes. It may be worth a try to unhook a programmer you are running? Wont cost anything anyhow.

 

[bry1216]

I had the erratic speedo and ABS light - turned out to be the ABS Controller.

 

[hpyman123]

Well here we go again. I puled the rear drums to check for adjustment and found a broken retainer spring on the right rear. It had rolled around in the drum and chewed up the front shoe a little and scored up the drum. I already had a new set of rear shoes so I got new drums a couple of hardware kits and rebuilt both back brakes. Result lights are still on. Brakes work great but still have the lights. I have scanned it unhooked batteries and checked connedtions so now I'm really at a loss for the problem I guess I may have to bite the bullet and have the dealer scan it.

 

[hpyman123]

I don't have an erratic speedo everyone is talking about just ABS and Brake lights