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When testing proves a wheel speed sensor has failed, Route 66 Auto Repair in Upland replaces it with the correct type for your vehicle and confirms the ABS light stays off on a road test. Some sensors come out with one bolt. Others are rusted into the knuckle or built into the wheel bearing, and we tell you which kind you have before we start.
Which kind of ABS sensor does your car use?
Older designs use a passive sensor: a magnet and a coil that generate their own signal as the tone ring teeth pass by. Most newer cars use active sensors, which are powered by the module and read a magnetic ring, often hidden inside the wheel bearing seal. The two are not interchangeable, and an off-spec sensor can set codes at low speed.
On many front-wheel-drive cars, the magnetic ring is part of the hub bearing. If that ring fails, the fix is a new hub assembly, not just a sensor, and a wheel bearing inspection is part of the job.
When is a new sensor the right fix?
- The sensor reads open or shorted on a resistance or signal test
- Live data shows no signal from one wheel while the wiring tests good
- The sensor body is cracked, melted or broken at the tip
- The lead is damaged too close to the sensor to repair
What about sensors rusted in place?
Sensors sit in a bore that collects rust. Pulled too hard, they snap and leave the tip behind. We use penetrating oil, patience and, when needed, careful drilling to clear the bore. If a sensor looks seized, we tell you before we try, since it can add time. The bore is cleaned and lightly greased so the new sensor sits at the right depth. When the problem turns out to be the wire and not the sensor, we switch to ABS wheel speed sensor repair instead.
Our ABS sensor replacement steps
Step 1: Confirm
We review the test from ABS system diagnostics that proved the sensor failed.
Step 2: Remove
The old sensor and lead come out, and the harness clips are saved or replaced.
Step 3: Clean and install
The bore is cleaned, the new sensor is seated and torqued, and the lead is routed clear of moving parts.
Step 4: Verify
Codes are cleared and a road test compares the new wheel speed reading with the other three.
What's included in ABS sensor replacement
Included on the work order
- 01Review of the failed-sensor test
- 02Correct sensor for your vehicle
- 03Mounting bore cleaning
- 04Wire routing and clip replacement as needed
- 05Code clear
- 06Road test with a wheel speed comparison
Do you need the sensor replaced now?
Need now: call
- A failed sensor on a vehicle you drive in the rain or use for towing
- A sensor fault that also disables stability control
Need later: book
- One failed sensor on a light-use car with normal braking, booked soon
- A working sensor with a scuffed outer jacket
What changes the price of a sensor job?
Location and design. A bolt-in front sensor is quick. A rusted-in sensor takes longer, and a sensor built into the hub means a bearing assembly. The written estimate names which of those applies. If you supply your own sensor, we inspect it first; labor is charged at book time and the part carries no warranty from us. AAA members who show their card save 10% on parts and labor, capped at $75.
Frequently asked questions
Can I buy a sensor and have you put it in?
Yes, and we will inspect it before installing. The part itself is not covered by warranty, and labor is charged at book time. If the new sensor does not clear the light, more testing is needed.
Why did my ABS light come back after the sensor was replaced?
Often the sensor was never the problem. A wire, connector or tone ring may be at fault, or the replacement was the wrong type. Testing the whole circuit usually finds it.
Do you replace the sensors on both sides at once?
Not by default. Sensors fail one at a time, so we replace the one that tested bad unless the other side shows damage as well.