For a complete wiring diagram Refer to Section 8W.When Monitored:With the ignition on.Set Condition:If the Left Rear Wheel Speed Sensor (WSS) circuit fails the diagnostic test.Possible CausesWIRING HARNESS, TERMINAL, CONNECTOR DAMAGE(B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE, GROUND, OR OPEN(B3) LEFT REAR WSS SIGNAL CIRCUIT SHORTED TO VOLTAGE, GROUND, OR OPEN(B3) LEFT REAR WSS SIGNAL CIRCUIT SHORTED TO (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUITLEFT REAR WSSANTI-LOCK BRAKES MODULE1. CHECK FOR DTC C1020–LEFT REAR WHEEL SPEED SENSOR CIRCUITThis DTC must be active for the results of this test to be valid.Turn the ignition on.With the scan tool, record and erase DTCs.Cycle the ignition switch from off to on.With the scan tool, read DTCs.Does the scan tool display: C1020–LEFT REAR WHEEL SPEED SENSOR CIRCUIT?YesGo To 2 NoThe condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.Refer to the ABS-INTERMITTENT CONDITION TEST. (Refer to 5 - BRAKES - DIAGNOSIS AND TESTING) 2. CHECK CONNECTOR/TERMINAL FOR DAMAGECheck all terminals for broken, bent, pushed out, or corroded terminals.Turn the ignition off.Inspect the Anti-Lock Brake Module harness connector, Left Rear WSS, and Left Rear WSS harness connector.Is the Left Rear WSS or any of the connectors/terminals damaged?YesRepair as necessary.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).NoGo To 33. CHECK (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT VOLTAGE

Disconnect the Left Rear WSS harness connector.Turn the ignition on.Measure the voltage of the (B4) Left Rear WSS 12 Volt Supply circuit.Is the voltage above 10.0 volts?YesGo To 6NoGo To 44. CHECK (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND

Turn the ignition off.Disconnect the Left Rear WSS harness connector.Disconnect the Anti-Lock Brake Module harness connector.Using a 12-volt test light connected to 12-volts, probe the (B4) Left Rear WSS Supply circuit.Does the test light illuminate brightly?YesRepair the (B4) Left Rear WSS Supply circuit for a short to ground.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).NoGo To 55. CHECK (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT FOR AN OPEN

Connect a jumper wire between ground and the (B4) Left Rear WSS Supply circuit in the Anti-Lock Brakes Module harness connector.Using a 12-volt test light connected to 12-volts, probe the (B4) Left Rear WSS Supply circuit.Does the test light illuminate brightly?YesReplace the Anti-Lock Brakes Module in accordance with the Service Information.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).NoRepair the (B4) Left Rear WSS Supply circuit for an open.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).6. CHECK (B3) LEFT REAR WSS SIGNAL CIRCUIT FOR A SHORT TO GROUND

Using a 12-volt test light connected to 12-volts, probe the (B3) Left Rear WSS Signal circuit.Does the test light illuminate brightly?YesRepair the (B3) Left Rear WSS Signal circuit for a short to ground.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).NoGo To 77. CHECK (B3) LEFT REAR WSS SIGNAL CIRCUIT FOR AN OPEN

Connect a jumper wire between ground and the (B3) Left Rear WSS Signal circuit in the Anti-Lock Brakes Module harness connector. Using a 12-volt test light connected to 12-volts, probe the (B3) Left Rear WSS Signal circuit.Does the test light illuminate brightly?YesGo To 8NoRepair the (B3) Left Rear WSS Signal circuit for an open.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).8. CHECK (B3) LEFT REAR WSS SIGNAL CIRCUIT SHORT TO VOLTAGE

Turn the ignition on.Remove all jumper wires.Measure the voltage between the (B3) Left Rear WSS Signal circuit and ground.Is the voltage above one volt?YesRepair the (B3) Left Rear WSS Signal circuit for a short to voltage.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).NoGo To9 9. CHECK (B3) LEFT REAR WSS SIGNAL CIRCUIT AND (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT SHORTED TOGETHER

Turn the ignition off.Measure the resistance between the (B3) Left Rear WSS Signal circuit and the (B4) Left Rear WSS Supply circuit.Is the resistance above 120 ohms?YesGo To 10NoRepair the (B3) Left Rear WSS Signal circuit and the (B4) Left Rear WSS Supply circuit for a short together.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).10. LEFT REAR WHEEL SPEED SENSORReplace the Left Rear Wheel Speed Sensor in accordance with the Service Information.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).Ensure brake capability is available before road testing.Road test the vehicle over 40 km/h (25 mph).Vehicle must be driven above 40 km/h (25 mph) for set conditions to be met.With the scan tool, read ABS DTCs.Did DTC C1020–LEFT REAR WHEEL SPEED SENSOR CIRCUIT reset?YesReplace the Anti-Lock Brakes Module in accordance with the Service Information.Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).NoTest Complete.