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Symptom:
*TRAC OFF INDICATOR NEVER/ALWAYS ON
POSSIBLE CAUSES
TRAC OFF SW GROUND OPEN
TRAC OFF SWITCH OPEN
TRAC OFF SWITCH SENSE CIRCUIT SHORT TO B+ OR OPEN
BCM -- NO TRAC OFF MESSAGE
CLUSTER INTERNAL FAULT-- TRAC OFF INDICATOR INOPERATIVE
CLUSTER-PERMANENT TRAC OFF INDICATOR
TRAC OFF SWITCH INTERNAL SHORT
TRAC OFF SWITCH SENSE CIRCUIT SHORT TO GROUND
BCM -- PERMANENT TRAC OFF MESSAGE
TEST ACTION APPLICABILITY
1Note: If any DTC's are present, they must be repaired prior to performing
this test.
Turn the ignition off.
Turn the ignition on.
Observe the TRAC OFF indicator.
Did the TRAC OFF indicator come on for several seconds then go out?All
Ye s®Go To 2
No. TRAC OFF Indicator does not come on.
Go To 5
No. TRAC OFF Indicator does not go out.
Go To 6
2 Disconnect the TRAC OFF Switch harness connector.
Using a 12-volt test light connected to 12-volts, check the TRAC OFF Switch Ground
circuit.
Does the test light illuminate brightly?All
Ye s®Go To 3
No®Repair the TRAC OFF Switch Ground circuit for an open.
Perform ABS VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the TRAC OFF Switch harness connector.
Turn the ignition on.
Connect and disconnect a jumper wire between TRAC OFF Switch Ground and
TRAC OFF Switch Sense circuits.
Does the TRAC OFF Indicator light and then go out?All
Ye s®Replace the TRAC OFF switch.
Perform ABS VERIFICATION TEST - VER 1.
No®Go To 4
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TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the TRAC OFF Switch harness connector.
Disconnect the CAB harness connector.
Turn the ignition on.
Check the TRAC OFF Switch Sense circuit for short to B+ and for an open.
Is the Sense circuit shorted or open?All
Ye s®Repair the TRAC OFF Switch Sense circuit for a short to battery
or for an open.
Perform ABS VERIFICATION TEST - VER 1.
No®Replace the Body Control Module in accordance with the Service
Information.
Perform ABS VERIFICATION TEST - VER 1.
5 Turn the ignition off.
NOTE: The purpose of this test is to perform the Instrument Cluster self
test.
Depress and hold the Odometer Reset Button.
Turn the Key from OFF to ON and then back to OFF.
Release the Odometer Reset Button.
Do the Instrument Cluster Indicators and Gauges activate and deactivate?All
Ye s®Replace the Body Control Module in accordance with the Service
Information.
Perform ABS VERIFICATION TEST - VER 1.
No®Replace the Instrument Cluster in accordance with the Service
Information.
Perform ABS VERIFICATION TEST - VER 1.
6NOTE: The purpose of this test is to perform the Instrument Cluster self
test.
Depress and hold the Odometer Reset Button.
Turn the Key from OFF to ON and then back to OFF.
Release the Odometer Reset Button.
Do the Instrument Cluster Indicators and Gauges activate and deactivate?All
Ye s®Go To 7
No®Replace the Instrument Cluster in accordance with the Service
Information.
Perform ABS VERIFICATION TEST - VER 1.
7 Turn the ignition off.
Disconnect the TRAC OFF Switch harness connector.
Turn the ignition on.
Does the TRAC OFF Indicator light and then go out?All
Ye s®Replace the TRAC OFF switch.
Perform ABS VERIFICATION TEST - VER 1.
No®Go To 8
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BRAKES (CAB)
*TRAC OFF INDICATOR NEVER/ALWAYS ON ÐContinued
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TEST ACTION APPLICABILITY
8 Turn the ignition off.
Disconnect the TRAC OFF Switch harness connector.
Disconnect the BCM C4 harness connector.
Check the TRAC OFF Switch Sense circuit for short to ground.
Is the Sense circuit shorted to ground?All
Ye s®Repair the TRAC OFF Switch Sense circuit for a short to ground.
Perform ABS VERIFICATION TEST - VER 1.
No®Replace the Body Control Module in accordance with the Service
Information.
Perform ABS VERIFICATION TEST - VER 1.
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BRAKES (CAB)
*TRAC OFF INDICATOR NEVER/ALWAYS ON ÐContinued
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Symptom:
*TRAC ON INDICATOR NEVER/ALWAYS ON
POSSIBLE CAUSES
CAB -- INTERNAL FAULT
CHECK TRACTION CONTROL SYSTEM
CLUSTER FAILS SELF TEST
CAB - NO TRAC MESSAGE
TEST ACTION APPLICABILITY
1NOTE: The DRBIIItmust be able to communicate with the CAB prior to
performing this test.
NOTE: Note: If any CAB DTC's are present, they must be repaired prior to
performing this test.
Perform the KEY-ON bulb test.
Did the TRAC Indicator illuminate and then go out?All
Ye s®Go To 2
No®Go To 3
2 Make sure the Traction Control system has not been deactivated with the TRAC OFF
switch.
NOTE: The purpose of this test is to determine if the Traction Control
system is operating.
With the DRBIIItin Inputs/Outputs, read the ABS Pump Motor voltage state.
Accelerate sufficient to cause drive wheel slip.
Does the TRAC Indicator illuminate and the DRBIIItdisplay approximately 9 volts?All
Ye s®The traction control system is functioning normally.
Perform ABS VERIFICATION TEST - VER 1.
No®Replace the Controller Antilock Brake in accordance with the
Service Information.
Perform ABS VERIFICATION TEST - VER 1.
3NOTE: The purpose of this test is to perform the Instrument Cluster self
test.
Depress and hold the Odometer Reset Button.
Turn the Key from OFF to ON and then back to OFF.
Release the Odometer Reset Button.
Do the Instrument Cluster Indicators and Gauges activate and deactivate?All
Ye s®Replace the Controller Antilock Brake in accordance with the
Service Information.
Perform ABS VERIFICATION TEST - VER 1.
No®Replace the Instrument Cluster in accordance with the Service
Information.
Perform ABS VERIFICATION TEST - VER 1.
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BRAKES (CAB)
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Verification Tests
ABS VERIFICATION TEST - VER 1 APPLICABILITY
1. Turn the ignition off.
2. Connect all previously disconnected components and connectors.
3. Ensure all accessories are turned off and the battery is fully charged.
4. Ensure that the Ignition is on, and with the DRBIII, erase all Diagnostic Trouble Codes from
ALL modules. Start the engine and allow it to run for 2 minutes and fully operate the system
that was malfunctioning.
5. Turn the ignition off and wait 5 seconds. Turn the ignition on and using the DRBIII, read
DTC's from ALL modules.
6. If any Diagnostic Trouble Codes are present, return to Symptom list and troubleshoot new
or recurring symptom.
7. If there are no DTC's present after turning ignition on, road test the vehicle for at least 5
minutes. Perform several antilock braking stops.
8. Caution: Ensure braking capability is available before road testing.
9. Again, with the DRBIIItread DTC's. If any DTC's are present, return to Symptom list.
10. If there are no Diagnostic Trouble Codes (DTC's) present, and the customer's concern can
no longer be duplicated, the repair is complete.
Are any DTC's present or is the original concern still present?All
Ye s®Repair is not complete, refer to appropriate symptom.
No®Repair is complete.
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VERIFICATION TESTS
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8.0 COMPONENT LOCATIONS
8.1 CONTROLLER ANTILOCK BRAKE (CAB)
8.2 DATA LINK CONNECTOR
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COMPONENT LOCATIONS
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8.3 FUSES
8.4 TRACTION CONTROL SWITCH
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COMPONENT LOCATIONS
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8.4.1 TRACTION CONTROL INDICATORS
8.5 WHEEL SPEED SENSORS
8.5.1 FRONT
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COMPONENT LOCATIONS