ABS Light showing on dash.

[Techventure]

I installed new rotors on my rear 1992 V6 Camry a month ago.

Yesterday the ABS light came on.
I asked my local mechanic about it and he said it was alright to keep driving the car as it was probably only a sensor.

Could anyone tell me what this sensor would be?

The brakes are still working fine.

Thanks .

[Brian R.]

Check to see if you damaged the wheel sensor or or disconnected the wiring for the ABS system. The sensor is located just behind the rotor on the axle carrier. It is the only thing with an electrical connection in that area.

[Techventure]

Thanks Brian.
I checked electrical to sensors and as far as I could tell they are alright.
Could they get dirt contaminated?

Murray

[Brian R.]

Sorry for the late response. Yes, the connections can get contaminated and/or dirty and cause this.

[Techventure]

Originally Posted by Brian R.

Sorry for the late response. Yes, the connections can get contaminated and/or dirty and cause this.

I'm also sorry for a late reply back.
How do you remove or open these sensors for cleaning? Also we are getting a small hammering noise at odd times and the ABS light goes off and then comes back on within a few seconds.In addition the front brakes seem to be carrying most of the braking load. The new rear pads are hardly worn.
I have a proportioning valve attached to the rear axle that was operated by a spring mechanism that is no longer on the car. I can move the lever by hand up or down but I don't know what difference it makes....seems to be none.
Thanks.

Murray

[Brian R.]

Originally Posted by Techventure

How do you remove or open these sensors for cleaning?

I don't believe they are user serviceable. The only service on them that you can perform is cleaning the contacts with electrical contact cleaner spray. You should buy new ones if they are malfunctioning and cleaning doesn't help.

Originally Posted by Techventure

In addition the front brakes seem to be carrying most of the braking load. The new rear pads are hardly worn.
I have a proportioning valve attached to the rear axle that was operated by a spring mechanism that is no longer on the car. I can move the lever by hand up or down but I don't know what difference it makes....seems to be none.

Make the load proportioning valve operational again. Replace any parts that are missing. Its lack of function is the source of your problem with the uneven pad wear.

[Techventure]

You can read the codes on the dash on a 1992 in this case with the ABS light and I found the code indicated a malfunction in the right front sensor. I removed the sensor and as you said the sensors are not serviceable. I went ahead and removed the sensor and cut back the sensor material down to the black and white wire clinched connectors to see what they look like. There is a magnet enclosed in the sensor about a 1/4" in diameter. I have no idea how this works accept for a concept that it must pick-up some signal from the wheel and sends it back to the ECU to control the ABS system

If you can shed further information on it i would be most appreciative..

NOW:

How to repair a cut-back ABS wheel sensor?

I cut two pieces of wire of the same gauge, a black and a white. carefully pried open the cliches holding the old wires and attached the new wires an re-clinched. To cover and waterproof the removed material I found a black rubber end tip you use on stools or a walking cane. The open diameter is about perfect to fit over the newly installed wire. When I do this I am filling the cane tip with a clear silicon. The other stripped ends of the wire will protrude through the silicon and tip and I will marry them to the sensor wire now dangling at the wheel.

Not something I would want to do everyday, but a learning experience.

I have also found a used load sensing proportioning valve and purchased it as you suggested. However they did not send the swivel part on the spring and rod end that attaches to the mount on the car frame. I'm now looking at how I can get around this.

Thanks.

[Brian R.]

Here's more reading material on brakes than you ever really needed. See particularly "Hydraulic Control" and "Anti-lock Brakes".

Fundamental Principles
Master Cylinder
Drum Brakes
Disc Brakes
Brake Booster
Parking Brake
Brake Diagnosis
Hydraulic Control
Anti-Lock Brakes
ABS Diagnosis
Other ABS Actuators
Traction Control System
Appendix

See http://www.autoshop101.com/ for more topics.

[Techventure]

Update on my ongoing ABS light staying on - 1992 V6 Camry.

1, It is still lit when the engine is on after replacing speed sensor in right front wheel.

2. The codes shown on the display panel show everything is correct. The engine light flashes as it should.

3. Tried disconnecting the negative lead on battery - light stays on.

4. Shorted Tc and E1 in box under hood after pulling pin and then pumping brake pedal 8 times within 3 seconds. Cycled on switch as recommended/ Did this procedure four times. - light still stays on.

5. Removed fuse to reset stored codes - light still stays on.

6. Disconnected positive battery lead and pushed on brake pedal to drain electricity. Re-attached positive terminal - light still stays on.

7. Removed fuse to reset codes after each of the above attempts - light still stays on.

If anyone can suggest another method to shut this ABS light off, I would appreciate the input.
Thanks.