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 339 of 4284

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.
Inspect the DCHA coolant hoses for restrictions, leakage, and damage.
Are the DCHA coolant hoses Ok?All
Ye s®Go To 3
No®Repair the DCHA coolant hoses as necessary 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.
Check that the engine's cooling system is operating properly in accordance with the
Service Information.
Is the engine's cooling system operating properly?All
Ye s®Go To 4
No®Repair the engine's cooling system in accordance with the Service
Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
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 reach normal operating temperature.
Turn the engine off.
Allow the engine's coolant to cool down to a temperature of 50ÉC (122ÉF).
Start the engine.
Allow the engine to reach normal operating temperature.
Turn the engine off.
View repairAll
Repair
Go To 5
310
CABIN HEATER
B1811 HEATER OVERHEATED ÐContinued
Page 340 of 4284
TEST ACTION APPLICABILITY
5WARNING: 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 the Cabin Heater fuse 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 6
311
CABIN HEATER
B1811 HEATER OVERHEATED ÐContinued
Page 341 of 4284

TEST ACTION APPLICABILITY
6WARNING: 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.
NOTE: The DCHA Control will store up to three DTCs in its memory.
NOTE: If the DCHA Control detects a new fault in the DCHA system, one
that is not already stored in its memory, the DCHA Control will clear the
oldest of the three stored DTCs, and it will store the new fault's DTC.
NOTE: If the DCHA control detects a reoccurrence of a stored fault, the
DCHA control will overwrite that fault's DTC with the most recent occur-
rence.
Turn the ignition on.
Set the Blend Control to the max cool position.
Turn the A/C - Heater Control Module's Power switch off.
With the DRBIIIt, erase Cabin Heater DTCs.
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 DCHA Field Mode Test with the engine off.
Failure to follow these instructions may result in internal damage to the
DCHA Heater Module.
With the DRBIIItin Cabin Heater, Systems Tests, select Field Mode and press Enter.
Set the Blend Control to the max heat position. Upon completion of the Field Mode
Test, proceed as follows:
With the DRBIIIt, read Cabin Heater and Active FCM DTCs.
Turn the Blower switch off and turn the A/C - Heater Control Module's Power switch
off.
Turn the engine off.
Are any DTCs present?All
Yes, B1811 & B1813 reset
Replace the DCHA Heater Module in accordance with the Service
Information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
Yes, B1811 Cleared, Other DTC(s) Present
Return to the symptom list and choose the DTC(s).
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Test Complete.
312
CABIN HEATER
B1811 HEATER OVERHEATED ÐContinued
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
Page 343 of 4284

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.
NOTE: The DCHA Control will store up to three DTCs in its memory.
NOTE: If the DCHA Control detects a new fault in the DCHA system, one
that is not already stored in its memory, the DCHA Control will clear the
oldest of the three stored DTCs, and it will store the new fault's DTC.
NOTE: If the DCHA control detects a reoccurrence of a stored fault, the
DCHA control will overwrite that fault's DTC with the most recent occur-
rence.
Turn the ignition on.
Set the Blend Control to the max cool position.
Turn the A/C - Heater Control Module's Power switch off.
With the DRBIIIt, record and erase Cabin Heater DTCs.
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 DCHA Field Mode Test with the engine off.
Failure to follow these instructions may result in internal damage to the
DCHA Heater Module.
With the DRBIIItin Cabin Heater, Systems Tests, select Field Mode and press Enter.
Set the Blend Control to the max heat position. Upon completion of the Field Mode
Test, proceed as follows:
With the DRBIIIt, read Cabin Heater and Active FCM DTCs.
Turn the Blower switch off and turn the A/C - Heater Control Module's Power switch
off.
Turn the engine off.
Are any DTCs present?All
Yes, B1813 & Other DTC(s) Present
Return to the symptom list and choose the additional DTC(s) first,
then diagnose B1813.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
Yes, B1813 Reset with No Other DTC(s)
Allow DCHA to cool. Inspect DCHA intake & exhaust pipes for
restrictions & obstructions. Repair as necessary. After repair,
repeat Test 2 of this procedure. If intake & exhaust pipes are Ok,
replace DCHA Heater Module in accordance with Service Info.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
Yes, B1813 Cleared, Other DTC(s) Present
Return to the symptom list and choose the DTC(s).
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Allow DCHA to cool. Inspect fuel line & coolant hoses for restric-
tions, obstructions, loose clamps, leakage, etc. Repair as neces-
sary. Check connectors. Clean & repair as necessary. Refer to
Service Manual for additional symptom diagnosis, if necessary.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
314
CABIN HEATER
B1813 HEATER IN LOCKOUT MODE ÐContinued
Page 344 of 4284

Symptom:
B1820 DOSING PUMP CIRCUIT: OPEN OR SHORT TO BATTERY
When Monitored and Set Condition:
B1820 DOSING PUMP CIRCUIT: OPEN OR SHORT TO BATTERY
When Monitored: With the ignition on.
Set Condition: This DTC will set if the DCHA Control detects no-load voltage on the
Dosing Pump circuit output pin.
POSSIBLE CAUSES
DOSING PUMP CONTROL CIRCUIT SHORTED HIGH
DOSING PUMP CONTROL CIRCUIT OPEN
GROUND CIRCUIT OPEN
DOSING PUMP
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.
NOTE: If present, diagnose and repair DTC B1811 Heater Overheated and
any other conditions relating to overheating before diagnosing this DTC.
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 Dosing Pump Control circuit and ground.
Is there any voltage present?All
Ye s®Repair the Dosing Pump Control circuit for a short to voltage.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
No®Go To 2
315
CABIN HEATER