I have been having problems with an intermittant ABS warning light. I have tried cleaning the front sensors and it still comes on, and seems to be related to braking on bumpy surfaces. I read in the FAQ that this is likely due to the:

"single rear sensor (single wire) that goes to the differential. The sensor sends the same signal to both speedometer and ABS units through one pair of wires leaves the sending unit. . The "over bumps" part is a good clue. That thing acts up over bumps first, and eventually breaks or becomes totally ineffective. Some days your system will work until you hit a bump and then BINGO- your ABS lite comes on and the speedometer fails! Play around with the sensor and connector and see if it might be your problem. It often is. "

This sounds just like my problem, but I am confused by the part at the end. It says to play around with the sensor and connector to see if this is the problem. Does this mean that I can maybe just clean the sensor and connector, or does a part need actual replacing?

Dear Johnb102,

Good p.m. and may this finds you well. I believe what is meant is this: when the ABS light is off - i.e., when the problem is not present - jack up the rear of the car, put jackstands into place, find the ABS sensor connector, and wiggle the wires/connector.

Wiggling the wire helps to determine if the wire's connection to the connector pin is good or not, or if there's break in the wire, inside the insulation, a rare phenomenon.

With the emergency brake engaged and the tranny in "Park", start the car. If the ABS light comes on, as a result of your having wiggled the wire, that means that a weak connection - due to dirt or corrosion - probably is the reason.

In that event, turn off the engine. Clean the connectors, and repeat the test. If the ABS light stays off, you've likely found the problem: a dirty/corroded connector. Drive the car. If, after a few weeks, the light stays out (except on start-up), you found/fixed the problem.

If the warning light stays on after start-up, then perhaps the wire is broken inside the insulation. To check for this, form the wire into a U shape, and move the U shape along the wire. If the U turns into a V, that suggests the wire is broken at the tip of the V. If that's so, replace the damaged wire.

If the wires are in good shape, and the connectors are clean, the last possibility is that the sensor has failed. Get a replacement, and install it.

That should fix the problem.

Hope this helps.

Yours faithfully,

spook

Thanks for the detailed explanation. Now I think I understand. My next problem is finding the ABS Sensor Connector so that I can wiggle it. Can you describe it, or better yet point me towards a picture?