Test I: DTC C1148/C1234 - Right Front Wheel Speed Sensor (Dynamic): Testing

NOTE: If no problems are found while testing sensor and circuits, check for intermittent conditions. See INTERMITTENT FAILURES under DIAGNOSIS & TESTING.

Turn ignition off. Connect NGS tester or scan tool. Turn ignition on. Retrieve DTCs. If DTC C1145 is retrieved, service DTC C1145 first and ignore other DTCs. See TEST H . If DTC C1145 is not set, go to next step.
With NGS, monitor ABCM PIDs LF_WSPD, RF_WSPD, and R_WSPD. Test drive vehicle at various speeds. If RF ABS sensor signal matches LF and rear ABS sensor signals, go to step 7. If ABS sensor signals do not match, go to next step.
NOTE: If a hard turn is made during test drive, some variation between all 3 sensors is expected. Rear speed signal should always fall between the left front and right front speed signals.
Raise and support vehicle. Rotate and carefully inspect sensor ring for damaged or missing teeth. Replace sensor ring if damaged. Clear DTCs and road test vehicle on rough roads and through car wash. Recheck system operation. If sensor ring is okay, go to next step.
Wiggle sensor and check for looseness. Tighten sensor as necessary. Clear DTCs and road test vehicle on rough roads and through car wash. Recheck system operation. If sensor is tight, go to next step.
Turn ignition off. Disconnect RF ABS sensor connector. Measure resistance between a known-good ground and both sensor terminals. If resistance is less than 10 k/ohms at either terminal, replace sensor. Clear DTCs and road test vehicle on rough roads and through car wash. Recheck system operation. If resistance is more than 10 k/ohms at both terminals, go to next step.
Turn ignition off. Disconnect ABCM connector. Install breakout box. Measure resistance between breakout box pins No. 10 and 22 (except late production Excursion), or No. 5 and 13 (late production Excursion). If resistance is less than 10 k/ohms, repair harness Yellow/Black and Yellow/Red wire circuit(s) for short to each other. Clear DTCs and road test vehicle on rough roads and through car wash. Recheck system operation. If resistance is more than 10 k/ohms, go to step 8.
Failure may be intermittent. See INTERMITTENT FAILURES under DIAGNOSIS & TESTING. If RF ABS sensor passed intermittent test, go to next step. If sensor did not pass test, repair sensor or circuit as needed. Clear DTCs and road test vehicle on rough roads and through car wash. Recheck system operation.
Turn ignition off. Remove RF ABS sensor. Inspect sensor for cracks or damage. Check connectors for debris, corrosion or water entry. Repair or replace, if needed. Clear DTCs and road test vehicle on rough roads and through car wash. Recheck system operation. If sensor conditions are okay, clear DTCs and road test vehicle on rough roads and through car wash. Recheck system operation.