Page 76 of 2305

TEST ACTION APPLICABILITY
2WARNING: TO AVOID PERSONAL INJURY OR DEATH, DISCONNECT THE
BATTERY AND WAIT TWO MINUTES BEFORE PROCEEDING.
Disconnect the Passenger Airbag connector(s).
NOTE: Check connectors - Clean and repair as necessary.
WARNING: IF THE AIRBAG CONTROL MODULE IS DROPPED AT ANY
TIME, IT MUST BE REPLACED. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND PERSONAL INJURY OR DEATH.
Connect the appropriate Load Tool to the Passenger Airbag connector(s).
WARNING: TO AVOID PERSONAL INJURY OR DEATH, THE IGNITION ON,
THEN RECONNECT THE BATTERY.
With the DRBIIIt, read the active Airbag Control Module DTC's.
Does the DRBIIItshow PASSENGER SQUIB 1 CIRCUIT SHORT TO BATTERY?All
Ye s!Go To 3
No!Replace Passenger Airbag in accordance with the Service Infor-
mation.
Perform AIRBAG VERIFICATION TEST - VER 1.
3WARNING: TO AVOID PERSONAL INJURY OR DEATH, TURN THE IGNI-
TION OFF, DISCONNECT THE BATTERY AND WAIT TWO MINUTES BE-
FORE PROCEEDING.
Disconnect the Load Tool from the Passenger Airbag connector(s).
Disconnect the Airbag Control Module connector(s).
NOTE: Check connectors - Clean and repair as necessary.
Connect the appropriate Load Tool Adaptor to the Airbag Control Module connec-
tor(s).
WARNING: AVOID PERSONAL INJURY OR DEATH, TURN IGNITION ON,
THEN RECONNECT THE BATTERY.
Measure the voltage on the Passenger Squib 1 Line 1 and Line 2 circuits between the
Passenger Airbag connector and ground.
Is there any voltage present?All
Ye s!Repair Passenger Squib 1 Line 1 or Line 2 circuit short to battery.
Perform AIRBAG VERIFICATION TEST - VER 1.
No!Go To 4
4WARNING: IF THE AIRBAG CONTROL MODULE IS DROPPED AT ANY
TIME, IT MUST BE REPLACED. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND PERSONAL INJURY OR DEATH.
If there are no possible causes remaining, view repair.All
Repair:
Replace the Airbag Control Module in accordance with Service
Instructions.
Perform AIRBAG VERIFICATION TEST - VER 1.
63
AIRBAG
PASSENGER SQUIB 1 SHORT TO BATTERY ÐContinued
Page 78 of 2305
Symptom:
PASSENGER SQUIB 1 SHORT TO GROUND
When Monitored and Set Condition:
PASSENGER SQUIB 1 SHORT TO GROUND
When Monitored: With the ignition on, the ACM monitors the resistance of the Passenger
Squib 1 circuits.
Set Condition: When the ACM detects a short to ground in either Passenger Squib 1
circuits.
POSSIBLE CAUSES
PAB SQUIB 1 CIRCUITS SHORT TO GROUND
PAB SQUIB 1 LINE 1 OR LINE 2 SHORT TO GROUND
ACM, PAB SQUIB 1 SHORT TO GROUND
STORED CODE OR INTERMITTENT CONDITION
ACTIVE CODE PRESENT
TEST ACTION APPLICABILITY
1 Turn the ignition on.
NOTE: Ensure the battery is fully charged.
NOTE: For the purpose of this test, the AECM and ORC modules will be
referred to as an ACM.
SELECT ACTIVE or STORED DTC:All
ACM - ACTIVE DTC
Go To 2
ACM - STORED DTC
Go To 5
NOTE: When reconnecting Airbag system components, the ignition must be
turned off and the battery must be disconnected.
65
AIRBAG
Page 81 of 2305
Symptom:
*AIRBAG WARNING INDICATOR FLASHING
POSSIBLE CAUSES
INITIALIZE AIRBAG CONTROL MODULE
ACTIVE CODE PRESENT
TEST ACTION APPLICABILITY
1 Erase all DTCs.
Cycle the ignition switch OFF then to ON.
With the DRBIIIt, read the active and stored DTCs.
Are all DTC8s erased?All
Ye s!With the DRBIIIt, perform Airbag Control Module initialization
to configure the ACM for this vehicle.
Perform AIRBAG VERIFICATION TEST - VER 1.
No!Select appropriate symptom from Symptom List.
68
AIRBAG
Page 82 of 2305

Symptom:
A. HEATER PRE-TEST
POSSIBLE CAUSES
NO RESPONSE FROM CABIN HEATER MODULE OR HEATER BOOSTER MODULE
CABIN HEATER MODULE OR HEATER BOOSTER MODULE DTC(S) PRESENT
AUTOMATIC TEMPERATURE CONTROL DTC(S) PRESENT
HEATER SYSTEM COMPONENTS
TEST ACTION APPLICABILITY
1WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
Turn the ignition off and either allow the engine coolant to cool down to at least 50ÉC
(122ÉF) or cold soak the engine.
CAUTION: When using a powered exhaust ventilation system, do not attach
the exhaust ventilation hose directly to the heater's exhaust pipe. Too much
suction can prevent heater operation.
When using a powered exhaust ventilation system, affix the ventilation hose to the
heater's exhaust pipe or to the vehicle in such a manor that the end of the ventilation
hose remains approximately three inches away from the end of the exhaust pipe.
When using a non-powered exhaust ventilation system, affix the ventilation hose
directly to the heater's exhaust pipe.
Turn the ignition on.
With the DRBIIIt, attempt to communicate with the Cabin Heater Module or Heater
Booster Module and the Automatic Temperature Control Module.
Does the DRBIIItdisplay: NO RESPONSE?All
Ye s!Refer to the Communication Category for the related symptom.
Perform HEATER VERIFICATION TEST - VER 1.
No!Go To 2
69
CABIN HEATER
Page 83 of 2305

TEST ACTION APPLICABILITY
2WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
WARNING: ALLOW THE HEATER ASSEMBLY TO COOL BEFORE PER-
FORMING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAIL-
URE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL
INJURY OR DEATH.
NOTE: The heater's control unit will store up to five DTCs in its memory.
NOTE: If the heater's control unit detects a new fault in the system, one that
is not already stored in its memory, it will clear the oldest of the five stored
DTCs, and it will store the new fault's DTC.
NOTE: If the heater's control unit detects a reoccurrence of a stored fault,
it will overwrite that fault's DTC with the most recent occurrence.
Turn the ignition on.
Verify that the Cabin Heater or Heater Booster is switched off.
Set the blend control to the max heat position and the mode control to the floor
position.
With the DRBIIIt, record and erase the Cabin Heater or Heater Booster Module's
DTCs.
Start the engine. Allow the engine to idle.
With the DRBIIIt, monitor for Cabin Heater Module or Heater Booster Module DTCs
while performing the following step.
NOTE: Do not disconnect the vehicle's battery or the heater's main power
supply while the heater is in operation or in run-down mode. Failure to
follow these instructions can result in excess emissions from the heater
during heater operation.
Switch the Cabin Heater or Heater Booster on. If operable, allow the heater to run
through at least one cycle of operation (approximately 10 minutes), and then switch
the heater off.
Does the DRBIIItdisplay any DTCs?All
Ye s!If the Heater In Lockout Mode DTC is present, record and erase
DTCs before performing any diagnostic procedures. Return to the
symptom list and choose the symptom(s).
Perform HEATER VERIFICATION TEST - VER 1.
No!Go To 3
70
CABIN HEATER
A. HEATER PRE-TEST ÐContinued
Page 84 of 2305

TEST ACTION APPLICABILITY
3WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
WARNING: ALLOW THE HEATER ASSEMBLY TO COOL BEFORE PER-
FORMING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAIL-
URE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL
INJURY OR DEATH.
Turn the ignition on.
With the DRBIIIt, read Automatic Temperature Control DTCs.
Are any DTCs present?All
Ye s!Refer to Heating & A/C information for the related symptom(s).
Perform HEATER VERIFICATION TEST - VER 1.
No!Allow heater assembly to cool. Inspect the fuel line, air intake and
exhaust, and coolant hoses for restrictions, obstructions, loose
clamps, leakage, etc. Repair as necessary. Check the harness
connectors and grounds. Clean and repair as necessary.
Perform HEATER VERIFICATION TEST - VER 1.
71
CABIN HEATER
A. HEATER PRE-TEST ÐContinued
Page 85 of 2305

Symptom:
CIRC PUMP CONTROL OPEN
POSSIBLE CAUSES
GROUND CIRCUIT OPEN
CIRCULATION PUMP RELAY HIGH SIDE CONTROL CIRCUIT OPEN
CIRCULATION PUMP RELAY
CABIN HEATER CONTROL UNIT
TEST ACTION APPLICABILITY
1WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
WARNING: ALLOW THE HEATER ASSEMBLY TO COOL BEFORE PER-
FORMING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAIL-
URE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL
INJURY OR DEATH.
CAUTION: DO NOT PERFORM THIS TEST UNLESS DIRECTED HERE BY
THE HEATER PRE-TEST. ALWAYS PERFORM THE HEATER PRE-TEST
PRIOR TO PERFORMING ANY OTHER TEST FOR THE RESULT TO BE
VALID.
Turn the ignition off.
Remove the Circulation Pump Relay from the relay center.
Measure the resistance between ground and the Ground circuit (Circulation Pump
Relay connector terminal 85).
Is the resistance below 5.0 ohms?All
Ye s!Go To 2
No!Repair the Ground circuit for an open.
Perform HEATER VERIFICATION TEST - VER 1.
72
CABIN HEATER
Page 86 of 2305

TEST ACTION APPLICABILITY
2WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
WARNING: ALLOW THE HEATER ASSEMBLY TO COOL BEFORE PER-
FORMING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAIL-
URE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL
INJURY OR DEATH.
Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Cabin Heater harness connector.
Remove the Circulation Pump Relay from the relay center.
Measure the resistance of the Circulation Pump Relay High Side Control circuit
between the Cabin Heater harness connector and the relay center (Circulation Pump
Relay connector terminal 86).
Is the resistance below 5.0 ohms?All
Ye s!Go To 3
No!Repair the Circulation Pump Relay High Side Control circuit for
an open.
Perform HEATER VERIFICATION TEST - VER 1.
3WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
Turn the ignition off.
Reconnect the Cabin Heater harness connector.
Install a substitute relay in place of the Circulation Pump Relay.
Turn the ignition on.
Verify that the Cabin Heater is switched off.
Set the blend control to the max heat position and the mode control to the floor
position.
With the DRBIIIt, erase the Cabin Heater Module's DTCs.
Start the engine. Allow the engine to idle.
With the DRBIII, monitor for Cabin Heater Module DTCs while performing the
following step.
NOTE: Do not disconnect the vehicle's battery or the heater's main power
supply while the heater is in operation or in run-down mode. Failure to
follow these instructions can result in excess emissions from the heater
during heater operation.
Switch the Cabin Heater on. If necessary, allow the heater to run through at least one
cycle of operation (approximately 10 minutes), and then turn the heater off.
Turn the engine off.
Does the DRBIIItdisplay: CIRC PUMP CONTROL OPEN?All
Ye s!Replace the Cabin Heater Assembly in accordance with the
Service Information. Reinstall the original Circulation Pump
Relay.
Perform HEATER VERIFICATION TEST - VER 1.
No!Replace the original Circulation Pump Relay in accordance with
the Service Information.
Perform HEATER VERIFICATION TEST - VER 1.
73
CABIN HEATER
CIRC PUMP CONTROL OPEN ÐContinued