Out of nowhere, my ABS light started coming on. Just the ABS light not the brake light. It’s off until I hit around 25 miles an hour and then stays on until I restart the car. It goes through the normal cycle on start up fine but then when I get to 25 it turns on. No noticeable changes with the brakes. They feel good and the same. The accumulator is only a couple years old and I just did a fresh brake flush last year when I put new calipers and rotors on the rear. Any ideas where to start? Cheapest option would be to start with an another change in fluid. Or maybe start looking at the speed sensor for cleanliness? I did check the fluid level that’s topped off and the electrical connections under it. We’re all very clean thanks.

 

Dan,

I'd suggest you first just run the ABS Blink Test and see what codes it tells you. You'll probably identify the problem straight away. This is the quickest and easiest test to perform and should be your first step.

My gut feel is that if both your lights are extinguishing after start up then your fluid level, pump, accumulator and pressure switch are functioning ok. If the ABS light comes on at c25 mph, then it sounds like it's a sensor, reluctor or associated wiring cable. The Blink test should help identify which corner.

Good luck

Paul

 

I did the blink test and I got 21, 31 and 75. Looking at the fault light code PDF I found, should I assume it is the front left sensor that is causing the issue or is there another issue that could be at play? Looking at the cost I may try to troubleshoot it if there is something that can be done.

thanks

 

I was able to examine the front left ABS sensor. The outer wire was dry rotted pretty badly and a section near the mounting grommet was missing the shielding. Messing with coaxial cable is not typically productive for me, but since the sensors are so expensive I decided to give it a try. I cut the line and added heat wrap down to the sensor and up to wheel well mount. Soldered the inner line back together, did my best to wrap that and then decided on adding aluminum foil to bridge the shielding. Wasn’t my initial plan, but ultimately I wasn’t left with much choice. I then shrink wrapped over the foil as well. To my dismay I no longer have an ABS light and I did about 20 miles today, so time will tell but hopefully it lasts.

 

Dismay? Looks like success to me! No reason for dismay!!!

 

Ha! Thank you. Grabbing the tin foil didn’t instill much confidence😂