Diagnostic Test

1) CHECK FOR DTC C100A-LEFT FRONT WHEEL SPEED SENSOR CIRCUIT
NOTE: This 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.

NOTE: The Anti-Lock Brake Module must sense ALL 4 wheels at 12 km/h (7.5 mph) before it will extinguish the ABS indicators.

Does the scan tool display: C100A-LEFT FRONT WHEEL SPEED SENSOR CIRCUIT?

Yes
1. Go To Step 2).
No
1. 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.
2. Refer to the ABS-INTERMITTENT CONDITION TEST. (Refer to BRAKES - DIAGNOSIS AND TESTING - ABS-INTERMITTENT CONDITION) .
2) CHECK CONNECTOR/TERMINAL FOR DAMAGE
NOTE: Check all terminals for broken, bent, pushed out, or corroded terminals.

Turn the ignition off.

Inspect the Anti-Lock Brake Module harness connector, Left Front WSS, and Left Front WSS harness connector.

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

Yes
1. Repair as necessary.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
No
1. Go To Step 3).
3) CHECK (B9) LEFT FRONT WSS SUPPLY CIRCUIT VOLTAGE

Fig 1: Checking (B9) Left Front WSS Supply Circuit Voltage
Courtesy of DAIMLERCHRYSLER CORP.

Disconnect the Left Front WSS harness connector.

Turn the ignition on.

Measure the voltage between the (B9) Left Front WSS Supply circuit and ground.

Is the voltage above 10 volts?

Yes
1. Go To Step 6).
No
1. Go To Step 4).
4) CHECK (B9) LEFT FRONT WSS SUPPLY CIRCUIT SHORT TO GROUND

Fig 2: Checking (B9) Left Front WSS Supply Circuit For Short To Ground
Courtesy of DAIMLERCHRYSLER CORP.

Disconnect the Anti-Lock Brake Module harness connector.

Using a 12-volt test light connected to 12-volts, probe the (B9) Left Front WSS Supply circuit.

Does the test light illuminate brightly?

Yes
1. Repair the (B9) Left Front WSS Supply circuit for a short to ground.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
No
1. Go To Step 5).
5) CHECK (B9) LEFT FRONT WSS SUPPLY CIRCUIT OPEN

Fig 3: Checking (B9) Left Front WSS Supply Circuit For Open
Courtesy of DAIMLERCHRYSLER CORP.

Connect a jumper wire between ground and the (B9) Left Front WSS Supply circuit in the Anti-Lock Brakes Module harness connector.

Using a 12-volt test light connected to 12-volts, probe the (B9) Left Front WSS Supply circuit.

Does the test light illuminate brightly

Yes
1. Go To Step 6).
No
1. Repair the (B9) Left Front WSS Supply circuit for an open.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
6) CHECK (B8) LEFT FRONT WSS SIGNAL CIRCUIT SHORT TO VOLTAGE

Fig 4: Checking (B8) Left Front WSS Signal Circuit For Short To Voltage
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition on.

Using a 12-volt test light connected between the (B8) Left Front WSS Signal circuit and ground.

Does the test light illuminate brightly?

Yes
1. Repair the (B8) Left Front WSS Signal circuit for a short to voltage.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
No
1. Go To Step 7).
7) CHECK (B8) LEFT FRONT WSS SIGNAL CIRCUIT SHORT TO GROUND

Fig 5: CHECKING (B8) LEFT FRONT WSS SIGNAL CIRCUIT FOR SHORT TO GROUND
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

If not done previously, disconnect the Anti-Lock Brake Module harness connector.

Using a 12-volt test light connected to 12-volts, probe the (B8) Left Front WSS Signal circuit.

Does the test light illuminate brightly?

Yes
1. Repair the (B8) Left Front WSS Signal circuit for a short to ground.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
No
1. Go To Step 8).
8) CHECK (B8) LEFT FRONT WSS SIGNAL CIRCUIT OPEN

Fig 6: CHECKING (B8) LEFT FRONT WSS SIGNAL CIRCUIT FOR OPEN
Courtesy of DAIMLERCHRYSLER CORP.

Connect a jumper wire between ground and the (B8) Left Front WSS Signal circuit in the Anti-Lock Brakes Module harness connector.

Using a 12-volt test light connected to 12-volts, probe the (B8) Left Front WSS Signal circuit.

Does the test light illuminate brightly?

Yes
1. Go To Step 9).
No
1. Repair the (B8) Left Front WSS Signal circuit for an open.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
9) CHECK (B8) LEFT FRONT WSS SIGNAL CIRCUIT AND (B9) LEFT FRONT WSS SUPPLY CIRCUIT SHORT TOGETHER

Fig 7: CHECKING (B8) LEFT FRONT WSS SIGNAL CIRCUIT AND (B9) LEFT FRONT WSS SUPPLY CIRCUIT SHORTED TOGETHER
Courtesy of DAIMLERCHRYSLER CORP.

Remove all jumper wires.

Measure the resistance between the (B8) Left Front WSS Signal circuit and the (B9) Left Front WSS Supply circuit.

Is the resistance above 5.0 ohms?

Yes
1. Go To Step 10).
No
1. Repair the (B8) Left Front WSS Signal circuit and the (B9) Left Front WSS Supply circuit for a short together.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
10) LEFT FRONT WHEEL SPEED SENSOR
Replace the Left Front Wheel Speed Sensor in accordance with the Service Information.

Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .

CAUTION: Ensure brake capability is available before road testing.

Road test the vehicle over 40 km/h (25 mph).

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

With the scan tool, read ABS DTCs.

NOTE: The Anti-Lock Brake Module must sense ALL 4 wheels at 12 km/h (7.5 mph) before it will extinguish the ABS indicators.

Did DTC C100A-LEFT FRONT WHEEL SPEED SENSOR CIRCUIT reset?

Yes
1. Replace the Anti-Lock Brakes Module in accordance with the Service Information.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
No
1. Test Complete.