Page 641 of 4284
Symptom:
SPEEDOMETER CHECKSUM FAILURE
POSSIBLE CAUSES
EMIC - INTERNAL ERROR
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, record and erase DTC's.
Turn the ignition off, wait 15 seconds, then turn the ignition on.
With the DRBIIIt, read DTCs.
Did the DTC return?All
Ye s®Go To 2
No®Test Complete.
2 If there are no possible causes remaining, view repair. All
Repair
Replace the EMIC.
Perform BODY VERIFICATION TEST - VER 1.
612
INSTRUMENT CLUSTER
Page 642 of 4284
Symptom:
TACHOMETER CHECKSUM FAILURE
POSSIBLE CAUSES
EMIC - INTERNAL ERROR
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, record and erase DTC's.
Turn the ignition off, wait 15 seconds, then turn the ignition on.
With the DRBIIIt, read DTCs.
Did the DTC return?All
Ye s®Go To 2
No®Test Complete.
2 If there are no possible causes remaining, view repair. All
Repair
Replace the EMIC.
Perform BODY VERIFICATION TEST - VER 1.
613
INSTRUMENT CLUSTER
Page 643 of 4284
Symptom:
TCM MESSAGE MISMATCH
POSSIBLE CAUSES
TCM COMMUNICATION FAILURE
INSTRUMENT CLUSTER, TCM MESSAGE MISMATCH
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, ensure PCI Bus communications with the TCM.
Is the TCM communicating on the PCI Bus?All
Ye s®Go To 2
No®Refer to COMMUNICATION category for the related symptom.
Perform BODY VERIFICATION TEST - VER 1.
2 If there are no possible causes remaining, view repair. All
Repair
Replace the Instrument Cluster.
Perform BODY VERIFICATION TEST - VER 1.
614
INSTRUMENT CLUSTER
Page 644 of 4284
Symptom:
TEMPERATURE GAUGE CHECKSUM FAILURE
POSSIBLE CAUSES
EMIC - INTERNAL ERROR
TEST ACTION APPLICABILITY
1 If there are no possible causes remaining, view repair. All
Repair
Replace the EMIC.
Perform BODY VERIFICATION TEST - VER 1.
615
INSTRUMENT CLUSTER
Page 645 of 4284

Symptom:
*ANY PCI BUS INDICATOR INOPERATIVE
POSSIBLE CAUSES
NO RESPONSE - PCI BUS
NO RESPONSE - INSTRUMENT CLUSTER
NO RESPONSE - ECM / PCM
INDICATOR INOPERATIVE
INSTRUMENT CLUSTER
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, select J1850 Module Scan.
Does the DRBIIItdisplay MIC PRESENT on the BUS?All
Ye s®Go To 2
No®Refer to the COMMUNICATION category and perform the ap-
propriate symptom.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition on.
With the DRBIIIt, Select Body, MIC, the MODULE DISPLAY.
Does the DRBIIItdisplay NO RESPONSE from MIC?All
Ye s®Refer to the symptom list for problems related to *NO RE-
SPONSE FROM THE INSTRUMENT CLUSTER.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 3
3 Turn the ignition on.
With the DRBIIIt, select Body, MIC, SYSTEM TESTS, PCM MONITOR.
Does the DRBIIItdisplay PCM INACTIVE on the BUS?All
Ye s®Refer to the symptom list for problems related to *NO RE-
SPONSE FROM THE POWERTRAIN CONTROL MODULE
(Gas) / or *NO RESPONSE FROM THE ENGINE CONTROL
MODULE (Diesel)
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 4
4NOTE: Diagnose and repair any PCM (gas) or ECM (diesel) DTCs before
proceeding with this test.
Perform the Instrument Cluster diagnostic Self Test.
Observe the indicator in question during the Self Test.
Did the indicator illuminate?All
Ye s®Refer to the appropriate Servic Information category to diagnose
the related system.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Instrument Cluster in accordance with the Service
Information.
Perform BODY VERIFICATION TEST - VER 1.
616
INSTRUMENT CLUSTER
Page 646 of 4284

Symptom:
ACCESSORY POWER OUTPUT #1 OPEN
When Monitored and Set Condition:
ACCESSORY POWER OUTPUT #1 OPEN
When Monitored: Continuously with the ignition on.
Set Condition: The FCM has detected an open in the Accessory Relay control circuit.
POSSIBLE CAUSES
FRONT CONTROL MODULE
FUSE & RELAY CENTER INTERNAL MALFUNCTION
ACCESSORY RELAY
FRONT CONTROL MODULE
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase the current Front Control Module DTC's.
Turn the ignition off, wait 10 seconds then turn the ignition on.
With the DRBIIIt, read the current Front Control Module DTC's.
Does the DRBIIItdisplay both the ACCESSORY POWER OUTPUT OPEN trouble
codes?All
Ye s®Go To 2
No®Go To 3
2 Turn the ignition off.
Disconnect the Accessory Relay from the Fuse & Relay Center.
Connect a known good relay to the Accessory Relay location in the Fuse & Relay
Center.
Turn the ignition on.
With the DRBIIIt, erase the current Front Control Module DTC's.
Turn the ignition off, wait 10 seconds then turn the ignition on.
With the DRBIIIt, read the current Front Control Module DTC's.
Does the DRBIIItdisplay both the ACCESSORY POWER OUTPUT OPEN trouble
codes?All
Ye s®Replace the Fuse and Relay Center.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the original Accessory Relay.
Perform BODY VERIFICATION TEST - VER 1.
617
INTELLIGENT POWER MODULE
Page 647 of 4284
TEST ACTION APPLICABILITY
3 Turn the ignition on.
With the DRBIIIt, read the current Front Control Module DTC's.
Does the DRBIIItdisplay the ACCESSORY POWER OUTPUT 1 OPEN trouble code?All
Ye s®Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 4
4 Turn the ignition on.
With the DRBIIIt, read the current Front Control Module DTC's.
Does the DRBIIItdisplay the ACCESSORY POWER OUTPUT #2 OPEN trouble
code?All
Ye s®Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®This symptom represents an internal malfunction in the Front
Control Module. The condition that caused this symptom is
currently not present.
Perform BODY VERIFICATION TEST - VER 1.
618
INTELLIGENT POWER MODULE
ACCESSORY POWER OUTPUT #1 OPEN ÐContinued
Page 648 of 4284

Symptom:
ACCESSORY POWER OUTPUT #1 SHORTED TO BATTERY
When Monitored and Set Condition:
ACCESSORY POWER OUTPUT #1 SHORTED TO BATTERY
When Monitored: Continuously with the ignition on.
Set Condition: The FCM has detected a short to battery voltage in the Accessory Relay
control circuit.
POSSIBLE CAUSES
FRONT CONTROL MODULE
FUSE & RELAY CENTER INTERNAL MALFUNCTION
ACCESSORY RELAY
FRONT CONTROL MODULE
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase the current Front Control Module DTC's.
Turn the ignition off, wait 10 seconds then turn the ignition on.
With the DRBIIIt, read the current Front Control Module DTC's.
Does the DRBIIItdisplay both ACCESSORY POWER OUTPUT SHORTED TO
BATTERY trouble codes?All
Ye s®Go To 2
No®Go To 3
2 Turn the ignition off.
Disconnect the Accessory Relay from the Fuse & Relay Center.
Connect a known good relay to the Accessory Relay location in the Fuse & Relay
Center.
Turn the ignition on.
With the DRBIIIt, erase the current Front Control Module DTC's.
Turn the ignition off, wait 10 seconds then turn the ignition on.
With the DRBIIIt, read the current Front Control Module DTC's.
Does the DRBIIItdisplay both ACCESSORY POWER OUTPUT SHORTED TO
BATTERY trouble codes?All
Ye s®Replace the Fuse and Relay Center.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the original Accessory Relay.
Perform BODY VERIFICATION TEST - VER 1.
619
INTELLIGENT POWER MODULE