
TEST ACTION APPLICABILITY
2WARNING: DO NOT OPERATE THE DCHA IN AN ENCLOSED AREA SUCH
AS A GARAGE THAT DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA's EXHAUST WHEN OPERATING THE
DCHA. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY OR DEATH.
WARNING: ALLOW THE DCHA ASSEMBLY TO COOL BEFORE PERFORM-
ING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAILURE TO
FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Cabin Heater Assist C1 harness connector.
Turn the ignition on.
Measure the voltage between the Cabin Heater Assist Control circuit and ground.
Is there any voltage present?All
Ye s®Go To 3
No®Replace the FCM in accordance with the Service Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
3WARNING: DO NOT OPERATE THE DCHA IN AN ENCLOSED AREA SUCH
AS A GARAGE THAT DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA's EXHAUST WHEN OPERATING THE
DCHA. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY OR DEATH.
WARNING: ALLOW THE DCHA ASSEMBLY TO COOL BEFORE PERFORM-
ING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAILURE TO
FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
Turn the ignition off.
Disconnect the battery in accordance with the Service information.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the IPM C3 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Cabin Heater Assist C1 and C2 harness connectors.
Measure the resistance between the Cabin Heater Assist Control circuit and the
Fused B(+) circuit.
Is the resistance below 10K ohms?All
Ye s®Repair the Cabin Heater Assist Control circuit for a short to the
Fused B(+) circuit.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Go To 4
330
CABIN HEATER
CABIN HEATER CONTROL CIRCUIT SHORT TO BATTERY (ACTIVE) Ð
Continued

TEST ACTION APPLICABILITY
4WARNING: DO NOT OPERATE THE DCHA IN AN ENCLOSED AREA SUCH
AS A GARAGE THAT DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA's EXHAUST WHEN OPERATING THE
DCHA. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY OR DEATH.
WARNING: ALLOW THE DCHA ASSEMBLY TO COOL BEFORE PERFORM-
ING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAILURE TO
FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
Turn the ignition off.
Disconnect the battery in accordance with the Service Information.
Remove the FCM in accordance with the Service Information.
Reconnect the IPM C3 harness connector.
Reconnect the battery in accordance with the Service Information.
Turn the ignition on.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Cabin Heater Assist C1 harness connector.
Measure the voltage between the Cabin Heater Assist Control circuit and ground.
Is there any voltage present?All
Ye s®Repair the Cabin Heater Assist Control circuit for a short to
voltage.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Replace the FCM in accordance with the Service Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
331
CABIN HEATER
CABIN HEATER CONTROL CIRCUIT SHORT TO BATTERY (ACTIVE) Ð
Continued

Symptom:
*CABIN HEATER INOPERABLE FROM A/C - HEATER MODULE
POSSIBLE CAUSES
DCHA ACTIVATION CRITERIA NOT MET
ATTEMPT TO COMMUNICATE WITH THE FCM AND THE HVAC MODULE
FCM OR HAVC DTCS PRESENT
VERIFY DCHA IS INOPERABLE FROM A/C - HEATER MODULE
A/C - HEATER CONTROL MODULE FAULT
TEST ACTION APPLICABILITY
1WARNING: DO NOT OPERATE THE DCHA IN AN ENCLOSED AREA SUCH
AS A GARAGE THAT DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA's EXHAUST WHEN OPERATING THE
DCHA. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY OR DEATH.
CAUTION: DO NOT PERFORM THIS TEST UNLESS DIRECTED HERE BY
THE CABIN HEATER PRE-TEST. ALWAYS PERFORM THE CABIN HEATER
PRE-TEST PRIOR TO PERFORMING ANY OTHER CABIN HEATER TEST
FOR THE RESULT TO BE VALID.
Verify that all of the following criteria was met during the attempt to activate the
DCHA from the A/C - Heater Control Module.
The engine was running.
The engine coolant temperature was below 66ÉC (151ÉF).
The vehicle's fuel tank had more than 1/8 of a tank of fuel.
The A/C - Heater Control Module's Power switch was on.
The Blend Control was set above 95% reheat.
Was all criteria met during the attempt to activate the DCHA from the A/C - Heater
Control Module?All
Ye s®Go To 2
No®Attempt to activate the DCHA when all of the operating criteria
are met.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
2WARNING: DO NOT OPERATE THE DCHA IN AN ENCLOSED AREA SUCH
AS A GARAGE THAT DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA's EXHAUST WHEN OPERATING THE
DCHA. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY OR DEATH.
Turn the ignition on.
With the DRBIIIt, attempt to communicate with the FCM and the HVAC Module.
Was the DRBIIItable to communicate with the FCM and the HVAC Module?All
Ye s®Go To 3
No®Refer to Communication for the related symptom(s)
Perform CABIN HEATER VERIFICATION TEST - VER 1.
332
CABIN HEATER

TEST ACTION APPLICABILITY
3WARNING: DO NOT OPERATE THE DCHA IN AN ENCLOSED AREA SUCH
AS A GARAGE THAT DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA's EXHAUST WHEN OPERATING THE
DCHA. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY OR DEATH.
Turn the ignition on.
With the DRBIIIt, check for FCM and HVAC DTCs.
Does the DRBIIItdisplay any FCM or HVAC DTCs?All
Ye s®For FCM DTCs, return to the symptom list and choose the
symptom(s). Also, refer to Intelligent Power Module for related
symptom(s). For HVAC DTCs, refer to Heater & A/C for related
symptom(s).
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Go To 4
4WARNING: DO NOT OPERATE THE DCHA IN AN ENCLOSED AREA SUCH
AS A GARAGE THAT DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA's EXHAUST WHEN OPERATING THE
DCHA. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY OR DEATH.
Start the engine.
Allow the engine to idle.
Turn the A/C - Heater Control Module's Power switch on.
Turn the Blower switch to the high speed position.
CAUTION: Do not activate the Diesel Cabin Heater Test with the engine off.
Failure to follow these instructions may result in internal damage to the
DCHA Heater Module.
NOTE: Do not disconnect the vehicle's battery or the DCHA's main power
supply while the DCHA is in operation or in run-down mode. Failure to
follow these instructions may result in excess emissions from the DCHA
during heater operation.
With the DRBIIItin HVAC, Systems Tests, select Diesel Cabin Heater Test and press
#1.
With the DRBIIItin HVAC, Systems Tests, Diesel Cabin Heater Test, read the Cabin
Heater Status.
Does the Status display: On?All
Ye s®Replace the FCM in accordance with the Service Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Replace the A/C - Heater Control Module in accordance with the
Service Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
333
CABIN HEATER
*CABIN HEATER INOPERABLE FROM A/C - HEATER MODULE Ð
Continued

Symptom:
*CHIME INOPERATIVE
POSSIBLE CAUSES
CHIME DRIVER CIRCUIT - OPEN
CHIME DRIVER CIRCUIT - SHORT TO GROUND
CHIME DRIVER CIRCUIT - SHORT TO VOLTAGE
INSTRUMENT CLUSTER
BCM
TEST ACTION APPLICABILITY
1 With the DRBIIIt, actuate the CHIME. (BCM actuator)
Does chime sound a warning?All
Ye s®Test Complete.
No®Go To 2
2 Disconnect the Instrument Cluster harness connector(s).
Disconnect the BCM harness connector(s).
Using a 12-volt test light connected to 12-volts, check the chime driver circuit for a
short to ground.
Does the test light illuminate brightly?All
Ye s®Repair the chime driver circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 3
3 Disconnect the Instrument Cluster harness connector(s).
Disconnect the BCM harness connector(s).
Using a DVOM connected to ground, check the chime driver circuit for a short to
voltage.
Is the voltage above 5.0 volts?All
Ye s®Repair the chime driver circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 4
4 Reconnect the BCM if disconnected in previous step.
Disconnect the Instrument Cluster harness connectors.
Using a 12-volt test light connected to 12-volts, check the chime driver circuit at the
Instrument Cluster connector.
With the DRBIIIt, actuate the CHIME. (BCM actuator)
Does the test light illuminate ON and OFF?All
Ye s®Replace the Instrument Cluster.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 5
334
CHIME

Symptom:
*PROBLEM WITH THE HIGH VEHICLE SPEED WARNING CHIME
POSSIBLE CAUSES
INCORRECT COUNTRY CODE PROGRAMMED IN BCM
BODY CONTROL MODULE
TEST ACTION APPLICABILITY
1 Note: The high speed warning chime is for Gulf Coast Countries only.
With the DRBIIItin Miscellaneous check the Body Control Module country code
setting.
Is the country code incorrect?All
Ye s®Program the correct country code setting.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace and program the Body Control Module in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
337
CHIME

POSSIBLE CAUSES
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1NOTE: For this code to be active, the DRB will not be able to communicate
with any modules on the vehicle (except the PCM).
NOTE: If this code is set and active it will be necessary to perform the PCI
Bus Communication Failure symptom.
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, wiggle the wiring
harnesses. This is to try and duplicate the complete bus failure condition.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform BODY VERIFICATION TEST - VER 1.
No®Test Complete.
341
COMMUNICATION
BCM, PCI BUS SHORTED TO BATTERY ÐContinued

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