Issues with ABS

Hey all,

I have been having an issue with my truck recently. Had an oil change done at the shop (it was free) and they told me I needed new CV axle boots because the ones I had were leaking grease. New axles were installed and got the truck back the other day and the ABS engages under 10 mph coming to a stop. When I got new tires a year ago the shop put on a new speed sensor and it fixed the issue (I thought). Each time the tires get taken off it seems to happen. I talked to the new shop I went to (where the CV axles were replaced). I had non-Toyota CV axles installed because they were much cheaper. According to the guy at the shop there is a sensor around the Toyota CV boots that works with the ABS system that the NAPA (I think) units don't have. My first question is has anyone else had this issue when replacing CV axles and my second question is does anyone know what may fix this issue? If it helps, the truck is a 2006 model double cab.

 

You can disable ABS all together by pulling both ABS fuses. Otherwise it sounds like you need to get the right CV axles with the tone rings on them. Although I'm not certain that where the tone rings should be. My truck doesn't have ABS.

The ABS activating at low speeds is somewhat common and if I remember correctly is due to one or more sensors that isn't sensitive enough to read at low speeds. Other sensors will read 4mph for example while the faulty one is reading 0mph. If you have a capable scan tool that can read live speed sensor data you may be able to narrow down your problem.

 

Interesting...wondering if it's just a faulty sensor...or maybe my reading of a sensor on the CV axle is wrong as well...? I've never heard of that and I wouldn't expect there to be one on the CV. I don't know of anyone who has a scan tool like that, but the shop did diagnose it with a scan tool and they are still picking their brains.

 

If it's a good shop with good equipment they should be able to hook up and drive around and monitor individual sensor data and see that they are all perfectly consistent at low speeds.

 

Okay, maybe I should ask and see if they did the scan while stationary...that could be the issue.

 

https://www.tundras.com/threads/abs-booster-goes-off-at-low-speed-stops.76185/#post-1939083
There's probably other threads about this on here but this is the first one I came across.

 

The wheel speed sensors are magnetic, and readily collect any iron filings, rust flakes, etc. This build-up on any of the sensors makes them read a weak signal especially at low speeds, making the ABS module think that wheel (or wheels) have locked up, thus activating the modulator solenoids and pump when braking at slow speeds.

Monitoring live data of the wheel speed sensors should show which one(s) are losing signal when driving at a 2mph snail’s pace. This sensor(s) should be removed, cleaned of any filings / rust flakes if needed, and the tone ring on the CV axle can also be inspected for damage through the sensor hole by rotating the wheel hub / CV axle.