Hey folks, I have had the RABS light and red Brake light up on my 92 F-150. I took it to the dealership and they checked it out and said I needed to replace my RABS valve which would possibly clear both lights. Well I replaced the valve , bled and flushed the brake fluid and the red brake light cleared. But the RABS light is still up. In the box with my valve there was a paper with some instructions and is said I may need to reset my computer before installing.

So my question, does my 92 F-150 computer brain need reset to clear this light, can it be reset?? If so is it something I can do or do I need to take it ti my local shop and have then connect to the computer to do it?

Of course Im not sure that I don't still have some other problem with my RABS system.

 

The RABS lamp and the RABS module is not connected to the Computer so no you do not have to reset the computer.
When both lights are on most of the time it is the MC switch saying you are low on brake fluid.

If all you have now is the yellow lamp on now is your transmission shifting OK if you have the E4OD and what about your speedometer?

Note that there is a reset switch on the valve you replaced. Did you push that switch?

 

More information on the RABS system:

How The Circuit Works

Operation
The Rear Anti-lock Brake System (RABS) continuously monitors rear wheel speed with a sensor mounted on the rear axle. When the teeth on an excitor ring (mounted on the ring gear) pass the sensor pole piece, an AC voltage with a frequency proportional to the average rear wheel speed is induced in the sensor circuit. If an impending lockup condition occurs during braking, the RABS modulates hydraulic pressure to the rear brakes to inhibit rear wheel lockup.

When the brake pedal is applied, the RABS Module senses the drop in rear wheel speed. If the rate of deceleration is too great (indicating an impending rear wheel lockup) the RABS Module activates the RABS Valve Assembly Isolation Solenoid, causing the isolation valve to close. With the isolation valve closed, the rear wheel cylinders are isolated from the master cylinder and the rear brake pressure cannot increase. If the rate of deceleration is still too great, the RABS Module will energize the dump solenoid with a series of rapid pulses to bleed off rear wheel cylinder fluid into an accumulator built into the RABS valve. This reduces the rear wheel cylinder pressure and allows the rear wheels to spin back up to vehicle speed.

When the driver releases the brake pedal at the end of a stop, the isolation valve deenergizes, and any fluid in the accumulator is returned to the master cylinder. Normal brake operation then resumes.

System Self-Test
The Rear Anti-lock Brake System has self-test capabilities similar to those in other electronic control systems. Two warning lamps, located in the instrument panel, alert the driver to a System malfunction. The red Brake Warning Lamp indicates a low fluid level or that the parking brake is on. The yellow Anti-lock Brake Indicator lights up for approximately two seconds when the Ignition Switch is first moved to ON or START for circuit prove out. The Indicator also lights up when the RABS Module detects a malfunction in the System.

The self-test feature contains thirteen codes that indicate the area of the malfunction. When a malfunction is detected, the RABS Control Module shuts down the System and the yellow Anti-lock Warning Lamp comes on. This permits normal braking. A code that can be retrieved by momentarily grounding the diagnostic pigtail and counting the flashes of the yellow light is then set in the system memory. If the key is turned off before the diagnostic test is performed, the code will be lost, and the light will remain out until another malfunction is detected. If more than one fault exists, only the first code recorded will be displayed. Additional codes will be output only after the first fault is corrected.

 

Also check that all rear brake lights are working correctly.

 

I picked the Bronco up the other day and both the ABS and brake light were illuminated. The brake lights were not functioning and the e4od transmission was shifting sporadically. Oh yeah and I had Zero rear brakes. So far I have changed the leaky master cylinder, bought a new accelerator cable ( was falling to pieces thought it might fix the transmission issue). I pulled the codes for the RABS and got a 4. We disconnected the resistor diode element and the code stayed in. Is this indicative of a bad RABS Hydraulic Unit?

 

I can speak toe the code, I took mine to my Local Ford dealership, because the Rear ABS light and Brake light were both lit. They told me after they reasd the code that I needed to replace the RABS, Rear Anti lock Brake valve. I did that,and the read Brake light went out right away. The yellow ABS light didn't go out till later. Some one told me the computer would purge the codes then recheck .

I have sold that truck since then. I would say if your having trouble, find a good local shop you can trust, and ask them if they can and would read your codes for you and tell you what it means. Once you know that, your set to change out what ever the problem part is.

 

I just bought this 1996 Econoline Club Wagon which is a factory conversion. It has 145k on it and it runs and drived great. Like new inside and out. I drove it around for a short time and the ABS light came on? Then the next day the brakes got mushy and at one time my wife said the ABS activated when stopping. I drove it and the brake was mushy bt no ABS activation. I checked the MC fluid level and it was fine. I checked for loose and hanging and found nothing. I did find that the front pads were in need of replacement and am doing that today. I am experenced in mechanics as I work for Ford in the 70s doing heavy line and electrical. I have little experence with the newer computer controlled cars. Anyone else with the same problem.
Thanks

 

The above thread is for the Rear Anti-lock Brake System (RABS).
You have a different system, 4-Wheel Anti-lock Brake System.

 

I have the dreaded light on my little half ton...where is the ground plug and where does it get grounded to?

 

Alright I found the plug. Now I have an 11, or 12, or 13 code. Pretty sure it's a 12 but can't find what the 11 and 13 are. Is there a chart to use?

 

Like this one?


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Deleted Deleted. Wrong info.

 

Yes sir! Thank you very much. Now I think maybe I have a short some where between the master cylinder. You wouldn't happen to have that schematic for that system?

 

Between the master cylinder and the abs module I meant.

 

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