Page 321 of 4284

Symptom:
RECIRC DOOR TRAVEL TOO LARGE (ACTIVE)
When Monitored and Set Condition:
RECIRC DOOR TRAVEL TOO LARGE (ACTIVE)
When Monitored: Ignition in RUN and IOD fuse installed.
Set Condition: This DTC is set when the ATC monitors the travel range during system
initialization and the measured range is greater than expected.
POSSIBLE CAUSES
CHECK THE ATC FOR DTCS
RECIRCULATION DOOR ACTUATOR
RECIRCULATION DOOR LINKAGE
AT C
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, read the active ATC DTCs.
Is the RECIRC DOOR NOT RESPONDING DTC set?All
Ye s®Return to the symptom list and choose the symptom.
With the DRBIIIt, reset the ATC after repair/replacement is
complete.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 2
2 Turn the ignition off.
Remove the Recirculation Door Actuator.
By hand, attempt to rotate the Recirculation Door Actuator in both directions.
Did the Recirculation Door Actuator turn in either direction?All
Ye s®Replace the Recirculation Door Actuator.
With the DRBIIIt, reset the ATC after repair/replacement is
complete.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 3
292
AUTOMATIC TEMPERATURE CONTROL
Page 323 of 4284

Symptom:
RECIRC DOOR TRAVEL TOO SMALL (ACTIVE)
When Monitored and Set Condition:
RECIRC DOOR TRAVEL TOO SMALL (ACTIVE)
When Monitored: Ignition in RUN and IOD fuse installed.
Set Condition: This DTC is set when the ATC monitors the travel range during system
initialization and the measured range is less than expected.
POSSIBLE CAUSES
CHECK THE ATC FOR DTCS
AT C
OBSTRUCTED RECIRC DOOR
RECIRCULATION DOOR ACTUATOR
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, read the active ATC DTCs.
Is the RECIRC DOOR NOT RESPONDING DTC set?All
Ye s®Return to the symptom list and choose the symptom.
With the DRBIIIt, reset the ATC after repair/replacement is
complete.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 2
2 Turn the ignition off.
Disconnect the Recirculation Door Actuator harness connector.
Connect a 12-volt Test Light between the Recirculation Door Driver (A) and (B)
circuits.
Turn the ignition on.
While monitoring the test light, press the recirculation control button from off to on.
Note: Observe test light for approximately 30 seconds.
Does the test light start to flash and stay flashing?All
Ye s®Go To 3
No®Replace the ATC.
With the DRBIIIt, reset the ATC after repair/replacement is
complete.
Perform BODY VERIFICATION TEST - VER 1.
294
AUTOMATIC TEMPERATURE CONTROL
Page 328 of 4284

Symptom:
B1000 CONTROL UNIT ERRONEOUS
When Monitored and Set Condition:
B1000 CONTROL UNIT ERRONEOUS
When Monitored: During DCHA activation.
Set Condition: This DTC will set if a fault occurs with the DCHA Control Unit's memory.
POSSIBLE CAUSES
DCHA CONTROL UNIT 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.
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.
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.
Turn the ignition off.
View repairAll
Repair
Replace the DCHA Heater Module in accordance with the Service
Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
299
CABIN HEATER
Page 329 of 4284

Symptom List:
B1800 NO START
B1801 FLAME OUT: DURING HEATING CYCLE
B1801 FLAME OUT: UNSTABLE OPERATION
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be B1800 NO START.
When Monitored and Set Condition:
B1800 NO START
When Monitored: After DCHA activation.
Set Condition: This DTC will set if the Flame Sensor resistance is not within the expected
parameters 160 sections after activation.
B1801 FLAME OUT: DURING HEATING CYCLE
When Monitored: After DCHA activation, and during subsequent start attempts.
Set Condition: This DTC will set if the Flame Sensor resistance is not within the expected
parameters.
B1801 FLAME OUT: UNSTABLE OPERATION
When Monitored: After DCHA activation.
Set Condition: This DTC will set if the Flame Sensor resistance is not within the expected
parameters.
POSSIBLE CAUSES
LOW FUEL LEVEL IN VEHICLE'S FUEL TANK
DOSING PUMP INOPERABLE, NO DOSING PUMP DTCS SET
DCHA FUEL LINE RESTRICTED/LEAKING/DAMAGED
DOSING PUMP
DCHA AIR INTAKE/EXHAUST RESTRICTED
DCHA HEATER MODULE FAULT
300
CABIN HEATER
Page 336 of 4284

Symptom:
B1802 POWER SUPPLY OUT OF RANGE: VOLTAGE ABOVE 15.5
VOLTS
When Monitored and Set Condition:
B1802 POWER SUPPLY OUT OF RANGE: VOLTAGE ABOVE 15.5 VOLTS
When Monitored: With the engine running.
Set Condition: This DTC will set if the DCHA's power supply voltage exceeds 15.5 volts
for longer than six seconds.
POSSIBLE CAUSES
VEHICLE'S CHARGING SYSTEM OVERCHARGING
DCHA CONTROL UNIT 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.
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.
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.
Check the vehicle's charging system for proper operation in accordance with the
Service Information.
Is the vehicle's charging system operating properly?All
Ye s®Replace the DCHA Heater Module in accordance with the Service
Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Repair the vehicle's charging system in accordance with the
Service Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
307
CABIN HEATER
Page 337 of 4284

Symptom:
B1803 FLAME DETECTED PRIOR TO COMBUSTION
When Monitored and Set Condition:
B1803 FLAME DETECTED PRIOR TO COMBUSTION
When Monitored: During DCHA start up.
Set Condition: This DTC will set if the Flame Sensor resistance is not within the expected
parameters.
POSSIBLE CAUSES
FLAME SENSOR 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.
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.
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.
Turn the ignition off.
View repairAll
Repair
Replace the DCHA Heater Module in accordance with the Service
Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
308
CABIN HEATER
Page 338 of 4284

Symptom:
B1811 HEATER OVERHEATED
When Monitored and Set Condition:
B1811 HEATER OVERHEATED
When Monitored: After DCHA activation, when the system is in a steady state of
operation.
Set Condition: This DTC will set if the Coolant Temperature Sensor resistance is not
within the expected parameters (coolant temperature in the Heater Module exceeds 125ÉC
[257ÉF]).
POSSIBLE CAUSES
DCHA HEATER MODULE FAULT
DCHA COOLANT HOSES RESTRICTED/LEAKING/DAMAGED
ENGINE'S COOLING SYSTEM FAULT
DCHA CONTROL UNIT FAULT
B1811 CLEARED, ADDITIONAL DTC(S) PRESENT
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.
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.
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.
Turn the ignition off.
NOTE: If there is an internal leak in the Heater Module, a continuous loud
chunking or grinding noise may have been heard coming from the DCHA
assembly during the Field Mode test.
Check for engine coolant continuously flowing out of the DCHA exhaust pipe.
Is engine coolant coming out of the DCHA exhaust pipe?All
Ye s®Replace the DCHA Heater Module in accordance with the Service
Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Go To 2
309
CABIN HEATER
Page 342 of 4284

Symptom:
B1813 HEATER IN LOCKOUT MODE
When Monitored and Set Condition:
B1813 HEATER IN LOCKOUT MODE
When Monitored: During DCHA activation.
Set Condition: This DTC will set if six continuous attempts to start heater operation fail
due to one or more faults in the DCHA system.
POSSIBLE CAUSES
B1813 AND ADDITIONAL DTC(S) PRESENT
B1813 RESET, NO ADDITIONAL DTC(S) PRESENT
B1813 CLEARED, ADDITIONAL DTC(S) PRESENT
STORED DCHA DTC(S) TEST COMPLETE
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.
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.
Set the Blend Control to the max heat position.
Remove Cabin Heater Fuse #15 from the IPM for a minimum of five seconds, then
reinstall the fuse. The DCHA may attempt to start.
Turn the Blower switch off and turn the A/C - Heater Control Module's Power switch
off.
Turn the engine off.
View repairAll
Repair
Go To 2
313
CABIN HEATER