2nd Gen Non-Engine/Transmission ABS and Brake light on

[GSykes]

ABS and brake light came on, removed speed sensor and cleaned it, now ABS & brake light come on and off at will. When I first start it it's out, run for a few miles then it comes back on. Any ideas? Can't get it to give me a code, ground pin 13 and nothing.



96 SLT extended cab, Claret Red/Driftwood, 3. 54 Spicer 70 LS, 96TH miles.





Problem turned out to be the diesel vacuum control valve, sits above the left front wheel well. Neither manual mentioned this valve in the brake system.

 

[whiteknight]

GSykes,

When I had my '96 (Traded it last week on a '03) my brake and ABS lights would come on and it wouldn't throw a code either.



What I ended up doing was when the lights would come on I discovered that if I unplugged the wire going to the proportioning valve (Under and to the left or driver side of master cylinder, has single wire) the lights would go off. I replaced the valve and that fixed my problem.

 

[Greystoke]

How I fixed mine...

There is numerous connectors that play into those lights turning on. Take each of these connectors and remove and reinstall them. That will hopefully get you a better connection



Brake switch under the dash

(3) connectors on the PCM

Antilock Controller and valves

Cruise control solenoid



Mine turned out to be a combination of things. I had a vacuum leak to the cruise control solenoid, a bad brake light switch, and a loose PCM connector. After repair have had no problems the last 6 months.



Greystoke

 

[GAmes]

When I had the ABS/brake light problem I could only retrieve a code if the lights were on. On mine a wire bundle connecter behind the left front tire (one of the wires went to the trailer brakes from the brake controller) was full of water and caused a dead short when the brakes were applied and the controller was installed. It would reset every time I turned the ignition off. If you have a brake controller try disconnecting it while trouble shooting.

 

[Koa Man]

On my truck the problem was a leaking vaccum line. Fixed the leak and no more lights on.