Normal Operation

WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

The wheel speed sensor and sensor ring generate a square wave signal to the ABS module that is proportional to wheel speed. The ABS module compares wheel speed inputs from all wheel speed sensors to determine an impending wheel lockup. Incorrect tire size can set these DTCs as well.

Voltage and ground signals are supplied to the wheel speed sensors from the ABS module. A damaged tone ring will cause DTC C1141, C1142, C1143 or C1144 to be set. An excessive wheel speed sensor air gap or a damaged tone ring will cause DTC C1233, C1234 C1235 or C1236 to be set.

DTC Description	Fault Trigger Conditions
DTC C1141 - Wheel Speed Sensor LF Tone Ring Tooth Missing Fault DTC C1142 - Wheel Speed Sensor RF Tone Ring Tooth Missing Fault DTC C1143 - Wheel Speed Sensor LR Tone Ring Tooth Missing Fault DTC C1144 - Wheel Speed Sensor RR Tone Ring Tooth Missing Fault	When the vehicle speed exceeds 20 km/h (12 mph), if the ABS module does not receive a signal from the wheel speed sensor, the DTC for that sensor will be set.
DTC C1233 - Wheel Speed Sensor LF Input Signal Missing DTC C1234 - Wheel Speed Sensor LF Input Signal Missing DTC C1235 - Wheel Speed Sensor LF Input Signal Missing DTC C1236 - Wheel Speed Sensor LF Input Signal Missing	When the vehicle speed exceeds 20 km/h (12 mph), if the ABS module does not receive a signal from the wheel speed sensor, the DTC for that sensor will be set.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
Wheel speed sensor
Wheel speed sensor ring
Wheel bearing
ABS module