C1020–LEFT REAR WHEEL SPEED SENSOR CIRCUIT

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 Causes

WIRING 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 CIRCUIT

LEFT REAR WSS

ANTI-LOCK BRAKES MODULE

Diagnostic Test

1.CHECK FOR DTC C1020–LEFT REAR WHEEL SPEED SENSOR CIRCUIT

NOTE: This DTC must be active for the results of this test to be valid.

Does the scan tool display: C1020–LEFT REAR WHEEL SPEED SENSOR CIRCUIT?

Yes

Go To 2

The 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 DAMAGE

NOTE: Check all terminals for broken, bent, pushed out, or corroded terminals.

Is the Left Rear WSS or any of the connectors/terminals damaged?

Yes

Repair as necessary.
Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).

Go To 3

3.CHECK (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT VOLTAGE

Is the voltage above 10.0 volts?

Yes

Go To 6

Go To 4

4.CHECK (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND

Does the test light illuminate brightly?

Yes

Repair the (B4) Left Rear WSS Supply circuit for a short to ground.
Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).

Go To 5

5.CHECK (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT FOR AN OPEN

Does the test light illuminate brightly?

Yes

Replace the Anti-Lock Brakes Module in accordance with the Service Information.
Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).

Repair 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

Does the test light illuminate brightly?

Yes

Repair the (B3) Left Rear WSS Signal circuit for a short to ground.
Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).

Go To 7

7.CHECK (B3) LEFT REAR WSS SIGNAL CIRCUIT FOR AN OPEN

Does the test light illuminate brightly?

Yes

Go To 8

Repair 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

Is the voltage above one volt?

Yes

Repair the (B3) Left Rear WSS Signal circuit for a short to voltage.
Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).

Go To9

9.CHECK (B3) LEFT REAR WSS SIGNAL CIRCUIT AND (B4) LEFT REAR WSS 12 VOLT SUPPLY CIRCUIT SHORTED TOGETHER

Is the resistance above 120 ohms?

Yes
10

No

Repair 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 SENSOR

(Refer to 5 - BRAKES - STANDARD PROCEDURE)

CAUTION: Ensure brake capability is available before road testing.

NOTE: Vehicle must be driven above 40 km/h (25 mph) for set conditions to be met.

Did DTC C1020–LEFT REAR WHEEL SPEED SENSOR CIRCUIT reset?

Yes

Replace the Anti-Lock Brakes Module in accordance with the Service Information.
Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).

Test Complete.