Wheel Speed Sensor RR Tone Ring Tooth Missing Fault
The rear right wheel speed sensor detected a missing tooth on its tone ring, which is like a gear with notches that tells the ABS system how fast that wheel is spinning. If a tooth breaks off, the sensor can't read the wheel speed properly, confusing the anti-lock brake system.
The ECU monitors the frequency and consistency of tooth pulses from the rear right wheel speed sensor. When a tooth is missing from the tone ring, the pulse pattern becomes irregular, creating a gap in the expected signal. The ECU compares actual pulse intervals against expected thresholds and triggers a fault when deviation exceeds tolerance.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Tooth pulse interval variance | Consistent pulse spacing within ±5% tolerance | Pulse gap exceeding 10% or missing pulse cycle detected |
| Sensor signal amplitude | 0.5–5.0 mV peak-to-peak | Irregular or dropout signal during wheel rotation |
Code C1144 is classified as a serious fault. If your check engine light is flashing — not just steady — pull over safely and do not continue driving. A flashing CEL indicates an active misfire or critical failure that can cause catalytic converter damage within minutes or permanent engine harm within miles. Contact a certified mechanic immediately. Do not attempt roadside repairs on high-severity codes unless you are trained to do so.
Once the fault is repaired, C1144 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.