00287 Rear Right ABS Wheel Speed Sensor G44: Mechanical Malfunction

What 00287 mechanical malfunction means

The ABS module constantly compares the speeds reported by all four wheels. When the rear right reading drops out, jumps or disagrees with the others in a way that points to a physical cause rather than a wiring fault, the module stores 00287 with a mechanical malfunction note. In most cases the problem lies in the parts that create the signal: the sensor tip, the gap between the sensor and its target ring, the ring itself, or the wheel bearing that keeps everything aligned. A new sensor fixes many of these faults, but not all of them, so replacing it without checking the surrounding parts often wastes money.

While the fault is active, ABS is disabled, and traction and stability control are usually switched off with it. The conventional hydraulic brakes still work, but the wheels can lock under hard braking on wet, icy or loose surfaces, so allow extra stopping distance. If the red brake warning lamp is also lit, the pedal feels soft or travels further than normal, or you hear grinding from the rear right wheel, stop using the vehicle and have the brakes inspected before driving further.

How the rear right speed sensor produces its signal

The sensor is mounted on the rear right hub carrier or axle and faces a rotating target. Older systems typically use a passive inductive sensor that reads the teeth of a steel tone ring. Newer systems often use an active sensor that reads a magnetic encoder ring, which on many designs is built into the wheel bearing seal. Each passing tooth or magnetic pole creates a pulse, and the module converts pulse frequency into wheel speed.

Accurate readings depend on a small, consistent air gap and an undamaged target. Rust building up under the sensor mounting can push it outward. Metallic dust from brake pads, rotors and friction material can coat a magnetic tip. A cracked or broken tooth, a corroded or lifting tone ring, or wobble from a worn wheel bearing makes the pulses weak or irregular. The module then sees a rear right speed that does not match the other three wheels and flags it as a mechanical problem. Passive sensors produce their weakest signal at low speed, so gap problems often show up when pulling away or coming to a stop.

What changes the diagnosis

Sensor type affects how it can be tested. A passive sensor generates its own signal and can be partly checked off the car, while an active sensor needs supply voltage from the module to produce any output, so it is normally judged through live data or an oscilloscope with the system connected. The location of the target ring matters too. On many front-wheel-drive models it is part of the rear hub or bearing assembly, while on all-wheel-drive versions it may sit on the rear drive shaft joint. A damaged ring may therefore mean replacing a bearing, hub or shaft component rather than just the sensor.

Recent work is an important clue. If 00287 appeared after brake pads, rotors or a caliper were replaced, suspect a sensor that was knocked, not fully seated, or a harness that was stretched or pinched. If it appeared after a bearing replacement, check that the correct bearing was fitted and that a magnetic encoder faces the sensor as intended. Mismatched tire sizes or a different spare on that corner can also upset the speed comparison. An intermittent fault that only returns over bumps points more toward wiring or a loose connection, while a fault that returns every drive suggests a damaged ring, excessive gap or failed sensor.

What the owner can check

Start with a scan tool that can read the ABS module. Record the full fault entry, including any freeze frame data, then clear it and note when it returns. If the tool shows live data, watch all four wheel speeds while driving slowly in a straight line on a quiet road or with a helper. A rear right reading that drops to zero, lags behind or flickers while the others stay steady confirms where the problem is and when it happens.

With the car securely supported on stands and the rear right wheel removed, inspect the sensor cable along its full route for chafing, cuts or contact with moving suspension parts, and check the connector for corrosion or loose pins. Rock the wheel at the top and bottom to feel for bearing play. Remove the sensor carefully, since they often seize in the bore, and check the tip for cracks or packed debris. Clean rust and dirt from the bore and mounting face so the sensor sits flush, then rotate the hub and look at the ring through the opening for missing teeth, cracks, heavy corrosion or uneven running.

If the sensor is clearly damaged, choose a replacement by confirming vehicle fitment against the part number or vehicle identification number, because left and right, front and rear, and active and passive versions are not interchangeable. Fit it without forcing, tighten the bolt to the specified torque and route the cable exactly as the original. During any future brake work, support the caliper instead of letting it hang on the hose or sensor harness, and keep brake fluid and cleaning sprays away from the connector.

Limitations and when to get professional help

Fault descriptions, test values, torque figures and allowable bearing play differ between models, model years and ABS module versions, and some scan tools word the same fault differently. Use the service information for your exact vehicle for wear limits, specifications and test procedures rather than generic values. A clean visual inspection does not rule out an internal sensor failure or a fine crack in a tone ring.

Have a professional take over if the wheel bearing has play, the tone ring is damaged or part of a drive shaft or hub, the wiring needs repair near moving suspension parts, or the code returns after a new sensor has been fitted. Seek help immediately if any braking symptom goes beyond warning lights, such as pulling, noise or a change in pedal feel. After any repair, clear the codes and complete a road test, confirming that the ABS light stays off and that 00287 does not return.