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7.0
DIAGNOSTIC INFORMATION AND
PROCEDURES
9
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Symptom List:
ANTI-LOCK BRAKE MODULE INTERNAL
CAB INTERNAL
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be ANTI-LOCK BRAKE MODULE
INTERNAL.
When Monitored and Set Condition:
ANTI-LOCK BRAKE MODULE INTERNAL
When Monitored: Ignition On - Continuously.
Set Condition: When there is a deviation from the expected result of a CAB internal self
check.
CAB INTERNAL
When Monitored: Ignition On - Continuously.
Set Condition: When there is a deviation from the expected result of a CAB internal self
check.
POSSIBLE CAUSES
INTERMITTENT CAB INTERNAL DTC
DAMAGED CAB/CAB HARNESS CONNECTOR
FUSED OPTIONAL EQUIPMENT RELAY OUTPUT CIRCUIT OPEN
FUSED B(+) CIRCUIT OPEN
GROUND CIRCUIT OPEN
ANTI-LOCK BRAKE CONTROLLER
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, read DTCs.
With the DRBIIIt, erase DTCs.
Turn the ignition off.
Turn the ignition on.
With the DRBIIIt, read DTCs.
Does this DTC reset?All
Ye s!Go To 2
No!Go To 6
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BRAKES (CAB)
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TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the CAB harness connector.
Inspect the CAB/CAB harness connector for damage.
Is there any broken, bent, pushed out, corroded or spread terminals?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Go To 3
3 Turn the ignition off.
Disconnect the CAB harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Optional Equipment
Relay Output circuit at the CAB harness connector.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Go To 4
No!Repair the Fused Optional Equipment Relay Output circuit for an
open.
Perform ABS VERIFICATION TEST - VER 1.
4 Turn the ignition off.
Disconnect the CAB harness connector.
Using a 12-volt test light connected to ground, check both Fused B(+) circuits at the
CAB harness connector.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Go To 5
No!Repair the Fused B(+) circuit for an open.
Perform ABS VERIFICATION TEST - VER 1.
5 Turn the ignition off.
Disconnect the CAB harness connector.
Using a 12-volt test light connected to 12-volts, check the CAB harness connector
Ground circuits.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Replace the Controller Antilock Brake in accordance with the
Service Information.
Perform ABS VERIFICATION TEST - VER 1.
No!Repair the Ground circuit for an open.
Perform ABS VERIFICATION TEST - VER 1.
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BRAKES (CAB)
ANTI-LOCK BRAKE MODULE INTERNAL ÐContinued
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TEST ACTION APPLICABILITY
6 Turn the ignition off.
Visually inspect the related wiring harness.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out, or corroded terminals.
Were any problems found?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Test Complete.
12
BRAKES (CAB)
ANTI-LOCK BRAKE MODULE INTERNAL ÐContinued
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Symptom:
BRAKE FLUID LEVEL
POSSIBLE CAUSES
INTERMITTENT DTC
BRAKE FLUID LEVEL SWITCH SIGNAL CIRCUIT SHORT TO GROUND
BRAKE FLUID LEVEL SWITCH
ANTI-LOCK BRAKE MODULE
TEST ACTION APPLICABILITY
1NOTE: Before proceeding, verify that the brake fluid is at the proper level
in accordance with the Service Information.
Turn the ignition on.
With the DRBIIIt, read DTCs.
With the DRBIIIt, erase DTCs.
Turn the ignition off.
Turn the ignition on.
With the DRBIIIt, read DTCs.
Does the DRBIIItdisplay BRAKE FLUID LEVEL?All
Ye s!Go To 2
No!Go To 4
2NOTE: The brake fluid must be at the proper level. Verify that the brake
fluid is at the proper level in accordance with the Service Information.
Turn the ignition off.
Disconnect the Brake Fluid Level Switch harness connector.
Measure the resistance between the terminals of the Brake Fluid Level Switch.
Is the resistance below 5.0 ohms?All
Ye s!Replace the Brake Fluid Level Switch in accordance with the
Service Information.
No!Go To 3
3 Turn the ignition off.
Disconnect the Brake Fluid Level Switch harness connector.
Disconnect the Instrument Cluster C2 harness connector.
Measure the resistance between ground and the Brake Fluid Level Switch signal
circuit.
Is the resistance below 5.0 ohms?All
Ye s!Repair the Brake Fluid Level Switch signal circuit for a short to
ground.
No!Replace the Antilock Brake Module in accordance with the
Service Information.
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BRAKES (CAB)
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TEST ACTION APPLICABILITY
4 Turn the ignition off.
Visually inspect the related wiring harness.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out, or corroded terminals.
Were any problems found?All
Ye s!Repair as necessary.
No!Test Complete.
14
BRAKES (CAB)
BRAKE FLUID LEVEL ÐContinued
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Symptom:
BRAKE PRESSURE SENSOR CIRCUIT
POSSIBLE CAUSES
BRAKE PRESSURE SENSOR CIRCUIT INTERMITTENT DTC
BRAKE PRESSURE SENSOR CIRCUIT SHORT TO VOLTAGE
BRAKE PRESSURE SENSOR CIRCUIT SHORT TO GROUND
BRAKE PRESSURE SENSOR CIRCUIT OPEN
BRAKE PRESSURE SENSOR
ANTI-LOCK BRAKE CONTROLLER
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Turn the ignition on.
With the DRBIIIt, read DTCs. Record DTC information.
NOTE: If a system undervoltage or overvoltage DTC is set along with this
DTC, diagnose the system voltage DTC first.
NOTE: Before continuing, make sure that the Brake Lamp switch is ad-
justed correctly and functioning properly. Adjust or replace the switch as
necessary in accordance with the Service Information.
With the DRBIIIt, erase DTCs.
Road test the vehicle and perform several braking maneuvers.
With the DRBIIIt, read DTCs.
Does this DTC reset?All
Ye s!Go To 2
No!Go To 6
2 Turn the ignition off.
Disconnect the Brake Pressure Sensor harness connector.
Disconnect the CAB harness connector.
Turn the ignition on.
Measure the voltage of the Brake Pressure Sensor signal circuit.
Measure the voltage of the Brake Pressure Sensor ground circuit.
Measure the voltage of the Brake Pressure Sensor 5 volt supply circuit.
Is there voltage present on any of the circuits?All
Ye s!Repair the Brake Pressure Sensor circuit(s) for a short to voltage.
No!Go To 3
3 Turn the ignition off.
Disconnect the Brake Pressure Sensor harness connector.
Disconnect the CAB harness connector.
Measure the resistance between ground and the Brake Pressure Sensor signal
circuit.
Measure the resistance between ground and the Brake Pressure Sensor 5 volt supply
circuit.
Is the resistance below 5.0 ohms for either circuit?All
Ye s!Repair the Brake Pressure Sensor circuit(s) for a short to ground.
No!Go To 4
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BRAKES (CAB)