Page 433 of 4284
Symptom:
*NO RESPONSE FROM FRONT CONTROL MODULE
POSSIBLE CAUSES
ATTEMPT TO COMMUNICATE WITH ANOTHER MODULE
OPEN GROUND CIRCUIT(S)
OPEN PCI BUS CIRCUIT
FRONT CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, attempt to communicate with the Airbag Control Module (ACM).
With the DRB, attempt to communicate with the Controller Antilock Brake (CAB)
module.
With the DRB, attempt to communicate with the Body Control Module (BCM).
Was the DRB able to I/D or communicate with any of the modules?All
Ye s®Go To 2
No®Refer to symptom list for problems related to the PCI Bus
Communication Failure.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Remove the Front Control Module from the IPM.
Measure the resistance between ground and both Ground circuits.
Is the resistance below 10.0 ohms for each measurement?All
Ye s®Go To 3
No®Repair the Ground circuit(s) for an open.
Perform BODY VERIFICATION TEST - VER 1.
404
COMMUNICATION
Page 434 of 4284

TEST ACTION APPLICABILITY
3Note: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Remove the Front Control Module from the IPM.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
Select DRB Standalone.
Select lab scope.
Select Live.
Select 12 volt square wave.
Press F2 for Scope.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the FCM connector.
Turn the ignition on.
Observe the voltage display on the DRB Lab Scope.
Does the voltage pulse from 0 to approximately 7.5 volts?All
Ye s®Go To 4
No®Repair the PCI Bus circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
4 If there are no possible causes remaining, view repair. All
Repair
Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
405
COMMUNICATION
*NO RESPONSE FROM FRONT CONTROL MODULE ÐContinued
Page 435 of 4284

Symptom:
*NO RESPONSE FROM LEFT SIACM
POSSIBLE CAUSES
INTERROGATE FCM
GROUND CIRCUIT OPEN
SIACM RUN/START DRIVER CIRCUIT OPEN
PCI BUS CIRCUIT OPEN
LEFT SIDE IMPACT AIRBAG CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, check the FCM for any DTC's.
Are any FCM DTC's present?All
Ye s®Refer to the appropriate category and perform the symptom.
Perform AIRBAG VERIFICATION TEST - VER 1.
No®Go To 2
2Ensure that the battery is fully charged.
Warning: TURN IGNITION OFF, DISCONNECT THE BATTERY AND WAIT
TWO MINUTES BEFORE PROCEEDING.
Disconnect the Left Side Impact Airbag Control Module harness connector.
Measure the resistance between ground and both Ground circuits.
Is the resistance below 5.0 ohms for both measurements?All
Ye s®Go To 3
No®Repair the Ground circuit for an open.
Perform AIRBAG VERIFICATION TEST - VER 1.
Note: When reconnecting Airbag system components, the ignition must be
turned off and the battery must be disconnected.
3Warning: TURN IGNITION OFF, DISCONNECT THE BATTERY AND WAIT
TWO MINUTES BEFORE PROCEEDING.
Disconnect the Left Side Impact Airbag Control Module harness connector.
Turn the ignition on and then reconnect the Battery.
Measure the voltage of the SIACM Run/Start Driver circuit.
Is the voltage above 6.0 volts?All
Ye s®Go To 4
No®Repair the SIACM Run/Start Driver circuit for an open.
Perform AIRBAG VERIFICATION TEST - VER 1.
Note: When reconnecting Airbag system components, the ignition must be
turned off and the battery must be disconnected.
406
COMMUNICATION
Page 436 of 4284

TEST ACTION APPLICABILITY
4NOTE: Ensure there is PCI bus communication with other modules. If not,
refer to the PCI Bus Communication Failure symptom and repair as
necessary.
WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
Disconnect the Left Side Impact Airbag Control Module harness connector.
Turn the ignition on and then reconnect the Battery.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
With the DRBIIItselect Pep Module Tools.
Select lab scope.
Select Live Data.
Select 12 volt square wave.
Press F2 for Scope, then enter to select channel.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the Left Side Impact Airbag Control Module connector.
Observe the voltage display on the DRB Lab Scope.
Does the voltage pulse from 0 to approximately 7.5 volts?All
Ye s®Go To 5
No®Repair the PCI Bus circuit for an open.
Perform AIRBAG VERIFICATION TEST - VER 1.
5 If there are no possible causes remaining, view repair. All
Ye s®Replace the Left Side Impact Airbag Control Module (LSIACM) in
accordance with the Service Information. WARNING: Make sure
the battery is disconnected and wait 2 minutes before proceeding.
Perform AIRBAG VERIFICATION TEST - VER 1.
407
COMMUNICATION
*NO RESPONSE FROM LEFT SIACM ÐContinued
Page 437 of 4284

Symptom:
*NO RESPONSE FROM ORC
POSSIBLE CAUSES
CHECKING FOR VOLTAGE AT ORC
ORC GROUND CIRCUIT OPEN
PCI BUS CIRCUIT OPEN
OCCUPANT RESTRAINT CONTROLLER
TEST ACTION APPLICABILITY
1NOTE: Check the FCM for DTC's. If DTC's are present, go to the appropriate
category and perform the DTC.
Ensure that the battery is fully charged.
WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
Disconnect the Occupant Restraint Controller harness connector.
Turn the ignition on and then reconnect the Battery.
Using a 12-volt test light connected to ground, probe the ORC Run Only Driver
Circuit and the ORC Run/Start Driver Circuit at the ORC connector.
NOTE: One open circuit will not cause a NO RESPONSE condition.
Is the test light illuminated on both circuits?All
Ye s®Go To 2
No®Repair the ORC Run Only Driver and ORC Run/Start Driver
circuits for an open.
Perform AIRBAG VERIFICATION TEST - VER 1.
NOTE: When reconnecting airbag system components, the ignition must be
turned off and the battery must be disconnected.
2Ensure that the battery is fully charged.
WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
Disconnect the Occupant Restraint Controller harness connector.
Measure the resistance between ground and the ground circuit.
Is the resistance below 5.0 ohms?All
Ye s®Go To 3
No®Repair the Ground circuit for an open.
Perform AIRBAG VERIFICATION TEST - VER 1.
When reconnecting Airbag system components, the ignition must be turned
off and the battery must be disconnected.
408
COMMUNICATION
Page 438 of 4284

TEST ACTION APPLICABILITY
3Note: Ensure there is PCI bus communication with other modules. If not,
refer to the PCI Bus Communication Failure symptom and repair as
necessary.
WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
Disconnect the Occupant Restraint Controller harness connector.
Turn the ignition on and then reconnect the Battery.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
With the DRBIIItselect Pep Module Tools.
Select lab scope.
Select Live Data.
Select 12 volt square wave.
Press F2 for Scope, then enter to select channel.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the Occupant Restraint Controller connector.
Observe the voltage display on the DRB Lab Scope.
Does the voltage pulse from 0 to approximately 7.5 volts?All
Ye s®Go To 4
No®Repair the PCI Bus circuit for an open.
Perform AIRBAG VERIFICATION TEST - VER 1.
4 If there are no possible causes remaining, view repair. All
Repair
Replace the Occupant Restraint Controller (ORC) in accordance
with the Service lnformation. WARNING: Make sure the battery
is disconnected and wait 2 minutes before proceeding.
Perform AIRBAG VERIFICATION TEST - VER 1.
409
COMMUNICATION
*NO RESPONSE FROM ORC ÐContinued
Page 439 of 4284

Symptom:
*NO RESPONSE FROM OVERHEAD CONSOLE
POSSIBLE CAUSES
GROUND CIRCUIT OPEN
IGNITION SWITCH OUTPUT CIRCUIT OPEN
FUSED B+ CIRCUIT OPEN
OPEN PCI BUS CIRCUIT
OVERHEAD CONSOLE
TEST ACTION APPLICABILITY
1NOTE: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Turn the ignition off.
Disconnect the Overhead Console harness connector.
Measure the resistance between ground and the ground circuit (cav 4).
Is the resistance below 5.0 ohms?All
Ye s®Go To 2
No®Repair the ground circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
2NOTE: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Turn the ignition off.
Disconnect the Overhead Console harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Ignition Switch Output
circuit.
Is the test light illuminated?All
Ye s®Go To 3
No®Repair the Ignition Switch Output circuit for an open. Refer to the
wiring diagrams located in the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
3NOTE: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Turn the ignition off.
Disconnect the Overhead Console harness connector.
Using a 12-volt test light connected to ground, probe the Fused B+ circuit.
Is the test light illuminated?All
Ye s®Go To 4
No®Repair the Fused B+ circuit for an open. Refer to the wiring
diagrams located in the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
410
COMMUNICATION
Page 440 of 4284

TEST ACTION APPLICABILITY
4Note: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Disconnect the Overhead Console harness connector.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
Select DRB Standalone.
Select lab scope.
Select Live Data.
Select 12 volt square wave.
Press F2 for Scope.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the Overhead Console connector.
Turn the ignition on.
Observe the voltage display on the DRB Lab Scope.
Does the voltage pulse from 0 to approximately 7.5 volts?All
Ye s®Go To 5
No®Repair the PCI Bus circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
5 If there are no possible causes remaining, view repair. All
Repair
Replace the Overhead Console.
Perform BODY VERIFICATION TEST - VER 1.
411
COMMUNICATION
*NO RESPONSE FROM OVERHEAD CONSOLE ÐContinued