ABS Controller?

[Mean_Green]

Hearing an occasional cavitation type noise (buzzing/vibrating) as well as a code turning on the ABS light.

Code reader mentions ABS controller, right front wheel speed sensor and brake switch circuit.

Dealer says no go, out of production and circulation. They have to try and find used or rebuilt.

Not looking to get one right now, but wondering about sources.

 

[Fless]

Would you list the specific codes that you're getting?

Any opportunity to graph the wheel speed sensors with a scanner?

 

[Mean_Green]

I'll have to wait to pull them again. Dealer cleared all old codes with a Tech2, so we could see what new ones will post.


I'll look at my HF scanner to see if they're still in memory.

No graphing that I know of.

 

[Eman85]

Common problem is ABS cycling when coming to a stop or at slow speeds. Common cause is worn hubs and or rust under the speed sensor where it mounts. It will set a code for a difference in speed readings at 1 wheel.

 

[Mean_Green]

Another one, I can see it, but can't get to it. Appears the rotor has to come off at the very least. Then, I'm not sure what.

Thinking about hitting it with BrakeClean in hopes of clearing dust or grime.

 

[Eman85]

Yours is simple, try a 3/4 ton or 1 ton where the rotor doesn't slide off of the hub. I have a pair of front wheel speed sensors for my truck sitting on a shelf where they have been for over 1 year as I keep putting it off because of the PIA it is to change them.

 

[me51]

These units are a pain to find used and no one seems to be able to rebuild them. The Kelsey Hayes EBC310 4WAL all look the same if they came out of a Yukon or Suburban or Tahoe or S10, but the software is different. The hydraulic unit below the EBCM/ABS module supposedly is also different depending on which vehicle it originally was put in.

I had the same issue on a '99 old-body style Suburban where the ABS showed a front right speed sensor open/intermittent circuit in hot weather, but the circuit was fine and the sensor was fine when tested with an oscilloscope and DVOM. In the end a used EBCM made the system work again. First I had an EBCM from a 97 Yukon, the ABS light went out but you could not access it with a scan tool and the braking behavior was very different. Some time later I found someone parting out a 99 Suburban, got the EBCM from that one and that works just like the original one (accessible with scan tool, hard brake behavior normal).

Common problem is ABS cycling when coming to a stop or at slow speeds. Common cause is worn hubs and or rust under the speed sensor where it mounts. It will set a code for a difference in speed readings at 1 wheel.

It does not always set a code, but rust lifting the sensor away from the magnet ring is a well-known issue on the GMT400 and I think even the GMT800 vehicles. Google "low speed abs activation chevrolet" and you'll find a lot of information about it.

 

[Mean_Green]

Found a pair of sensors for about $20.

Shop replaced both for $40/wheel.

Reset/cleared the codes also.

Drove it quite a bit today, lots of stops, no light.

 

[Mean_Green]

3 months since the wheel sensors were replaced.

No ABS light after several trips, no cavitation noise or feel.