Page 1177 of 4284
TEST ACTION APPLICABILITY
3 With the DRBIIIt, read DTCs.
Did the DTC reoccur?All
Ye s®
No®Go To 4
4 Turn the ignition off.
Visually inspect wheel speed sensor.
Visually inspect tone wheel.
Visually inspect wiring harness.
Visually inspect brakes for locking up due to lining contamination or overheating.
Inspect all Components for defects which may cause a Signal DTC to set.
Is any Component Damaged?All
Ye s®Repair as necessary. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No®Test Complete.
20
BRAKES (CAB)
LEFT REAR WHEEL SPEED SIGNAL FAILURE ÐContinued
Page 1178 of 4284

Symptom:
PUMP CIRCUIT FAILURE
When Monitored and Set Condition:
PUMP CIRCUIT FAILURE
When Monitored: Ignition on. The CAB commands the pump on at 20 km/h (12 mph) to
check its operation, if the brake switch is not applied. If the brake is applied, the test will
run at 40 km/h (25 mph). The CAB monitors pump voltage every 7 milliseconds.
Set Condition: The DTC is stored when the CAB detects: 1) Improper voltage decay after
the pump was turned off. 2) Pump not energized by the CAB, but voltage is present for 3.5
seconds. 3) Pump is turned on by the CAB, but without sufficient voltage to operate it.
POSSIBLE CAUSES
PUMP HARNESS DISCONNECTED
CAB - PUMP MOTOR RUNNING CONTINUOUSLY
ABS PUMP MOTOR INTERMITTENT DTC
GROUND CIRCUIT HIGH RESISTANCE
FUSED B(+) CIRCUIT OPEN
GROUND CIRCUIT OPEN
CAB - INTERNAL FAULT
CAB - SETTING FALSE CODE
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Turn the ignition on.
Monitor the pump motor for continuous operation.
Is the pump motor running continuously?All
Ye s®Replace the Controller Anti-Lock Brake in accordance with the
Service Information. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No®Go To 2
2 Turn the ignition on.
With the DRBIIIt, read DTC's.
With the DRBIIIt, erase DTC's.
Turn the ignition off.
Turn the ignition on.
With the DRBIIIt, actuate the ABS pump motor.
Did the Pump Motor operate when actuated?All
Ye s®Go To 3
No®Go To 4
21
BRAKES (CAB)
Page 1179 of 4284

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?All
Ye s®Repair as necessary. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No®Replace the Controller Anti-Lock Brake in accordance with the
Service Information. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
4 Check the short Wiring Harness between the ABS Pump and the CAB.
Check for disconnect and damage.
Is the harness disconnected or damaged?All
Ye s®Reconnect or repair the Pump Harness as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No®Go To 5
5 Turn the ignition off.
Disconnect CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the CAB ground circuits.
Is the resistance below 1.0 ohm?All
Ye s®Go To 6
No®Repair the ground circuit for an open. The vehicle must be driven
at 25 km/h (15 mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
6 Turn the ignition on.
With the DRBIIIt, enable pump motor actuation.
NOTE: Pump motor will not operate, but voltage will be applied.
Measure the voltage drop across the ABS ground circuit connection, with pump motor
actuation enabled.
Is the voltage below 0.1 volt?All
Ye s®Go To 7
No®Repair the Ground circuit for high resistance. The vehicle must be
driven at 25 km/h (15 mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
22
BRAKES (CAB)
PUMP CIRCUIT FAILURE ÐContinued
Page 1180 of 4284
TEST ACTION APPLICABILITY
7 Turn the ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Pump Motor Fused B+
circuit.
Does the test light illuminate brightly?All
Ye s®Go To 8
No®Repair the Fused B(+) circuit for an open. The vehicle must be
driven at 25 km/h (15 mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
8 If there are no possible causes remaining, view repair. All
Repair
Replace the Controller Anti-Lock Brake in accordance with the
Service Information. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
23
BRAKES (CAB)
PUMP CIRCUIT FAILURE ÐContinued
Page 1181 of 4284

Symptom:
RIGHT FRONT WHEEL SPEED SIGNAL FAILURE
When Monitored and Set Condition:
RIGHT FRONT WHEEL SPEED SIGNAL FAILURE
When Monitored: Wheel speed comparison is checked at drive off or every 7 milliseconds
(ms). Wheel speed continuity is checked every 7 milliseconds. Wheel speed phase length
supervision is checked every 7 milliseconds.
Set Condition: If, during an ABS stop, the CAB commands any valve solenoid on for an
extended length of time, and does not see a corresponding wheel speed change, the
Diagnostic Trouble Code (DTC) is set. The DTC can also set if the signal is missing or
erratic.
POSSIBLE CAUSES
SENSOR OR TONE WHEEL CONCERN
DTC INTERMITTENT
RIGHT FRONT WHEEL SPEED SENSOR INOPERATIVE
CAB - WON'T RESPOND TO RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
INTERMITTENT SIGNAL DTC
TEST ACTION APPLICABILITY
1 With the DRBIIIt, erase DTCs.
Turn the ignition off.
Start the engine.
Slowly accelerate as straight as possible from a stop to 24 km/h (15 mph).
Using the DRBIIIt, monitor the Right Front Wheel Speed Sensor while an assistant
drives the vehicle.
With the DRBIIIt, monitor all wheel speed sensors.
Is Right Front WSS Signal 0 km/h (0 mph) or differing from others by more than 5
km/h (3 mph)?All
Ye s®Go To 2
No®Go To 3
2 Inspect the Right Front Wheel Speed Sensor, Connector and Tone Wheel.
NOTE: Inspect components for damage and correct installation.
Are there any visible Sensor, Connector or Tone Wheel concerns?All
Ye s®Correct the sensor, connector or tone wheel concern as necessary.
The vehicle must be driven at 25 km/h (15 mph) to extinguish the
ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No®Replace the Right Front Wheel Speed Sensor in accordance with
the Service Information. The vehicle must be driven at 25 km/h
(15 mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
24
BRAKES (CAB)
Page 1182 of 4284
TEST ACTION APPLICABILITY
3 With the DRBIIIt, read DTCs.
Did the DTC reoccur?All
Ye s®Replace the Controller Antilock Brake in accordance with the
Service Information. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No®Go To 4
4 Turn the ignition off.
Visually inspect wheel speed sensor.
Visually inspect tone wheel.
Visually inspect wiring harness.
Visually inspect brakes for locking up due to lining contamination or overheating.
Inspect all Components for defects which may cause a Signal DTC to set.
Is any Component Damaged?All
Ye s®Repair as necessary. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No®Test Complete.
25
BRAKES (CAB)
RIGHT FRONT WHEEL SPEED SIGNAL FAILURE ÐContinued
Page 1183 of 4284

Symptom:
RIGHT REAR WHEEL SPEED SIGNAL FAILURE
When Monitored and Set Condition:
RIGHT REAR WHEEL SPEED SIGNAL FAILURE
When Monitored: Wheel speed comparison is checked at drive off or every 7 milliseconds
(ms). Wheel speed circuit continuity is checked every 7 milliseconds. Wheel speed phase
length supervision is checked every 7 milliseconds.
Set Condition: If, during an ABS stop, the CAB commands any valve solenoid on for an
extended length of time, and does not see a corresponding wheel speed change, the
Diagnostic Trouble Code (DTC) is set. The DTC can also set if the signal is missing or
erratic.
POSSIBLE CAUSES
SENSOR OR TONE WHEEL CONCERN
DTC INTERMITTENT
RIGHT REAR WHEEL SPEED SENSOR INOPERATIVE
INTERMITTENT SIGNAL DTC
TEST ACTION APPLICABILITY
1 With the DRBIIIt, erase DTCs.
Turn the ignition off.
Start the engine.
Slowly accelerate as straight as possible from a stop to 24 km/h (15 mph).
Using the DRBIIIt, monitor the Right Rear Wheel Speed Sensor while an assistant
drives the vehicle.
With the DRBIIIt, monitor all wheel speed sensors.
Is Right Rear WSS Signal 0 km/h (0 mph) or differing from others by more than 5
km/h (3 mph)?All
Ye s®Go To 2
No®Go To 3
2 Inspect the Right Rear Wheel Speed Sensor, Connector and Tone Wheel.
NOTE: Inspect components for damage and correct installation.
Are there any visible Sensor, Connector or Tone Wheel concerns?All
Ye s®Correct the sensor, connector or tone wheel concern as necessary.
The vehicle must be driven at 25 km/h (15 mph) to extinguish the
ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No®Replace the Left Rear Wheel Speed Sensor in accordance with the
Service Information. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
26
BRAKES (CAB)
Page 1184 of 4284
TEST ACTION APPLICABILITY
3 With the DRBIIIt, read DTCs.
Did the DTC reoccur?All
Ye s®
No®Go To 4
4 Turn the ignition off.
Visually inspect wheel speed sensor.
Visually inspect tone wheel.
Visually inspect wiring harness.
Visually inspect brakes for locking up due to lining contamination or overheating.
Inspect all Components for defects which may cause a Signal DTC to set.
Is any Component Damaged?All
Ye s®Repair as necessary. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No®Test Complete.
27
BRAKES (CAB)
RIGHT REAR WHEEL SPEED SIGNAL FAILURE ÐContinued