Pinpoint Test B: Wheel Speed Sensor Erratic Signal Faults: Notes

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Refer to CRUISE CONTROL for schematic and connector information.

Normal Operation and Fault Conditions

The wheel speed sensor uses the encoder (tone wheel) on the wheel bearing to generate a square wave signal proportional to wheel speed that is sent to the ABS module. The wheel bearing, encoder and wheel speed sensor must be undamaged and free from any contamination to produce a clean signal for use by the ABS module. Also, all 4 tires and wheels must be of the same manufacturer recommended size for the wheel speed sensor to generate an accurate wheel speed signal.

REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
ABS C0033:07	Right Front Tone Wheel: Mechanical Failures	These Diagnostic Trouble Codes (DTCs) set in continuous memory and on-demand if there is damage to the wheel speed sensor or encoder ring, After ABS initialization and when vehicle speed is above 48 km/h (30 mph), the ABS module monitors the raw wheel speed sensor signal for a cyclically reoccurring gap or slope in the signal. This indicates a possible missing tooth in the encoder ring. If the signal is incorrect for more than 1 minute, the DTC is set.
ABS C0036:07	Left Rear Tone Wheel: Mechanical Failures	These Diagnostic Trouble Codes (DTCs) set in continuous memory and on-demand if there is damage to the wheel speed sensor or encoder ring, After ABS initialization and when vehicle speed is above 48 km/h (30 mph), the ABS module monitors the raw wheel speed sensor signal for a cyclically reoccurring gap or slope in the signal. This indicates a possible missing tooth in the encoder ring. If the signal is incorrect for more than 1 minute, the DTC is set.
ABS C0039:07	Right Rear Tone Wheel: Mechanical Failures	These Diagnostic Trouble Codes (DTCs) set in continuous memory and on-demand if there is damage to the wheel speed sensor or encoder ring, After ABS initialization and when vehicle speed is above 48 km/h (30 mph), the ABS module monitors the raw wheel speed sensor signal for a cyclically reoccurring gap or slope in the signal. This indicates a possible missing tooth in the encoder ring. If the signal is incorrect for more than 1 minute, the DTC is set.
ABS C0030:07	Left Front Tone Wheel: Mechanical Failures	These Diagnostic Trouble Codes (DTCs) set in continuous memory and on-demand if there is damage to the wheel speed sensor or encoder ring, After ABS initialization and when vehicle speed is above 48 km/h (30 mph), the ABS module monitors the raw wheel speed sensor signal for a cyclically reoccurring gap or slope in the signal. This indicates a possible missing tooth in the encoder ring. If the signal is incorrect for more than 1 minute, the DTC is set.
ABS C0031:2F	Left Front Wheel Speed Sensor: Signal Erratic	Sets when the wheel speed sensor is damaged, if the encoder is missing or damaged, if there is an excessive gap between the sensor and encoder or high frequency interference and it affects the sensor input to the ABS module.
ABS C0031:64	Left Front Wheel Speed Sensor: Signal Plausibility Failure	Sets when the wheel speed sensor is damaged, if the encoder is missing or damaged, if there is an excessive gap between the sensor and encoder, if the wrong sensor is installed (bi-directional versus uni-directional) or if the tire size is incorrect for the vehicle affects the sensor input to the ABS module.
ABS C0034:2F	Right Front Wheel Speed Sensor: Signal Erratic	Sets when the wheel speed sensor is damaged, if the encoder is missing or damaged, if there is an excessive gap between the sensor and encoder or high frequency interference and it affects the sensor input to the ABS module.
ABS C0034:64	Right Front Wheel Speed Sensor: Signal Plausibility Failure	Sets when the wheel speed sensor is damaged, if the encoder is missing or damaged, if there is an excessive gap between the sensor and encoder, if the wrong sensor is installed (bi-directional versus uni-directional) or if the tire size is incorrect for the vehicle affects the sensor input to the ABS module.
ABS C0037:2F	Left Rear Wheel Speed Sensor: Signal Erratic	Sets when the wheel speed sensor is damaged, if the encoder is missing or damaged, if there is an excessive gap between the sensor and encoder or high frequency interference and it affects the sensor input to the ABS module.
ABS C0037:64	Left Rear Wheel Speed Sensor: Signal Plausibility Failure	Sets when the wheel speed sensor is damaged, if the encoder is missing or damaged, if there is an excessive gap between the sensor and encoder, if the wrong sensor is installed (bi-directional versus uni-directional) or if the tire size is incorrect for the vehicle affects the sensor input to the ABS module.
ABS C003A:2F	Right Rear Wheel Speed Sensor: Signal Erratic	Sets when the wheel speed sensor is damaged, if the encoder is missing or damaged, if there is an excessive gap between the sensor and encoder or high frequency interference and it affects the sensor input to the ABS module.
ABS C003A:64	Right Rear Wheel Speed Sensor: Signal Plausibility Failure	Sets when the wheel speed sensor is damaged, if the encoder is missing or damaged, if there is an excessive gap between the sensor and encoder, if the wrong sensor is installed (bi-directional versus uni-directional) or if the tire size is incorrect for the vehicle affects the sensor input to the ABS module.
ABS C1A95:64	Wheel Speed Sensor: Signal Plausibility Failure	This DTC is set when the ABS module monitoring determines an implausible ABS control activation has been requested for more than 1 second.

Possible Sources

Wiring, terminals or connectors
Incorrect or mismatched tire
Tire pressure
Wheel speed sensor
Wheel speed sensor encoder ring
Wheel bearing
ABS