2001 CHRYSLER VOYAGER fan

ating and the combustion air fan operation is sus-
pended for 3 seconds. Subsequently, the combustion
air fan speed is increased in two ramps within 56
seconds to nearly full load operation. After a stabi-
lization phase of 15 seconds, the combustion air fan
speed is again increased in a ramp within 50
seconds to nearly full load. After reaching full load
fuel delivery, the glow plug is deactivated and the
combustion air fan operation is increased to full
load. During the subsequent 45 seconds, as well as
in normal operation, the glow plug functions as a
flame sensor to monitor the flame condition. After
all these events, the automatically controlled heat-
ing operation starts.
In case of a no flame or a flame out condition, a
restart is automatically initiated. If the no flame
condition persists, fuel delivery is stopped and the
heater enters an error lockout mode with a run-
down of the combustion air fan. This will set one or
more DTCs in the DCHA Control's memory. If six
continuous attempts to start the heater fail due to
one or more faults in the DCHA system, the heater
enters a heater lockout mode. This will set DTC
B1813 along with any other fault(s) that the DCHA
Control identified.
3.10.3.2 HEATING
During the automatically controlled heating op-
eration, when the coolant temperature reaches
72ÉC (162ÉF), the heater will switch to a part load
operation. When the coolant temperature reaches
75ÉC (167ÉF) or if the heater runs for longer than 76
minutes the heater will switch to a control idle
period. If the coolant temperature drops to 71ÉC
(160ÉF) during a control idle period, the heater will
perform a regular starting sequence into full load
operation. A drop in coolant temperature to 65ÉC
(149ÉF) during part load operation will cause the
heater to switch to a full load operation.
3.10.3.3 DEACTIVATION
The DCHA will deactivate if the:
²engine is turned off.
²coolant temperature reaches 75ÉC (167ÉF).
²heater runs longer than 76 minutes.
²fuel tank has less than 1/8 of a tank of fuel.
²Power switch on the A/C ± Heater Control Module
is off.
²Blend Control on the A/C ± Heater Control Mod-
ule is set below 75% reheat.
When the heater is deactivated, the combustion
stops and a run-down sequence begins. During the
run-down sequence, the combustion air fan contin-
ues operation to cool down the heater. The fan is
automatically switched off after the run-down se-
quence is complete. The run-down time and thecombustion air fan speed depend on the heater
operating condition at the time of deactivation.
Run-down time is approximately 175 seconds when
deactivated in full load operation and approxi-
mately 100 seconds when deactivated in part load
operation.
3.10.4 DIAGNOSTICS
The DCHA is fully addressable with the DRBIIIt.
System tests include a Field Mode Test to activate
the DCHA for diagnostic testing purposes. The
DCHA Control will store up to three DTCs in its
memory. If the Controller detects a new fault in the
DCHA system, one that is not already stored in its
memory, it will clear the oldest of the three stored
DTCs, and it will store the new fault's DTC. If the
Controller detects a reoccurrence of a stored fault, it
will overwrite that fault's DTC with the most recent
occurrence.
3.11 INSTRUMENT CLUSTER
The Instrument Cluster receives and sends mes-
sages to other modules via the PCI bus circuit. The
indicator lamps will illuminate briefly for a bulb
check when the ignition is turned from off to run.
All of the gauges receive their information via the
PCI bus from the powertrain control module and
body control module.
The gauges and the LEDs are not individually
replaceable thereby requiring complete replace-
ment of the Instrument Cluster if a repair is neces-
sary. In the event that the Instrument Cluster loses
communication with other modules on the PCI bus,
the cluster will display ªno busº in the VF display.
The Trip/Reset button is used to switch the dis-
play from trip to total mileage. Holding the button
when the display is in the trip mode will reset the
trip mileage. This button is also used to put the
cluster in self-diagnostic mode. The odometer dis-
play uses blue-green vacuum fluorescent digital
characters.
On base vehicles, the Instrument Cluster has
three gauges: Speedometer, Fuel and Engine Cool-
ant Temperature. A red dot moves transversely
through openings in the Instrument Cluster face
(P-R-N-D-2-1) to indicate the gear selected.
With all other models, the Instrument Cluster
also includes a Tachometer and uses a vacuum-
fluorescent shift indicator.
The odometer display and door/liftgate ajar indi-
cators turn on when a door is opened to assist both
the customer and service technician to view the
odometer without turning the ignition on.
21
GENERAL INFORMATION

Symptom List:
AC PRESSURE TOO HIGH (STORED)
AC PRESSURE TOO LOW (STORED)
DRIVER BLEND DOOR NOT RESPONDING (STORED)
DRIVER BLEND DOOR RANGE TOO LARGE (STORED)
DRIVER BLEND DOOR TRAVEL TOO SMALL (STORED)
FRONT IR SENSOR AND CONTROL HEAD MISMATCH (STORED)
FRONT IR SENSOR CHANGE TOO LARGE (STORED)
FRONT IR SENSOR HIGH (STORED)
FRONT IR SENSOR LOW (STORED)
FRONT IR SENSOR NOT CALIBRATED (STORED)
FRONT KEYBOARD COMMUNICATION FAULT (STORED)
FRONT KEYBOARD FAULT (STORED)
FRONT MODE DOOR NOT RESPONDING (STORED)
FRONT MODE DOOR TRAVEL TOO LARGE (STORED)
FRONT MODE DOOR TRAVEL TOO SMALL (STORED)
PASS BLEND DOOR NOT RESPONDING (STORED)
PASS BLEND DOOR TRAVEL TOO LARGE (STORED)
PASS BLEND DOOR TRAVEL TOO SMALL (STORED)
PCI BUS SHORTED HIGH (STORED)
PCI BUS SHORTED LOW (STORED)
REAR BLEND DOOR NOT RESPONDING (STORED)
REAR BLEND DOOR RANGE TOO LARGE (STORED)
REAR BLEND DOOR TRAVEL TOO SMALL (STORED)
REAR FAN POT OPEN (STORED)
REAR FAN POT SHORTED (STORED)
REAR IR SENSOR HIGH (STORED)
REAR IR SENSOR LOW (STORED)
REAR IR SENSOR NOT CALIBRATED (STORED)
REAR KEYBOARD FAULT (STORED)
REAR MODE DOOR NOT RESPONDING (STORED)
REAR MODE DOOR TRAVEL TOO LARGE (STORED)
REAR MODE DOOR TRAVEL TOO SMALL (STORED)
REAR MODE POT OPEN (STORED)
REAR MODE POT SHORTED (STORED)
RECIRC DOOR NOT RESPONDING (STORED)
RECIRC DOOR TRAVEL TOO LARGE (STORED)
RECIRC DOOR TRAVEL TOO SMALL (STORED)
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be AC PRESSURE TOO HIGH
(STORED).
When Monitored and Set Condition:
226
AUTOMATIC TEMPERATURE CONTROL

REAR BLEND DOOR NOT RESPONDING (STORED)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC does not receive feedback pulses within 5
seconds of the drive voltage being applied.
REAR BLEND DOOR RANGE TOO LARGE (STORED)
When Monitored: With the ignition on and the 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.
REAR BLEND DOOR TRAVEL TOO SMALL (STORED)
When Monitored: With the ignition on and the 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.
REAR FAN POT OPEN (STORED)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the rear blower switch value and it is
above 250 A/D counts.
REAR FAN POT SHORTED (STORED)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the rear fan switch value and it is below
5 A/D counts.
REAR IR SENSOR HIGH (STORED)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the Rear IR Sensor value and it is above
250 A/D counts.
REAR IR SENSOR LOW (STORED)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the Rear IR Sensor value and it is below
5 A/D counts.
REAR IR SENSOR NOT CALIBRATED (STORED)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC cannot read the IR sensor values or the IR
sensor values are not within a defined range of the HVAC air door motor counts.
229
AUTOMATIC TEMPERATURE CONTROL
AC PRESSURE TOO HIGH (STORED) ÐContinued

Symptom List:
REAR FAN POT OPEN (ACTIVE)
REAR FAN POT SHORTED (ACTIVE)
REAR IR SENSOR HIGH (ACTIVE)
REAR IR SENSOR LOW (ACTIVE)
REAR MODE POT OPEN (ACTIVE)
REAR MODE POT SHORTED (ACTIVE)
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be REAR FAN POT OPEN (ACTIVE).
When Monitored and Set Condition:
REAR FAN POT OPEN (ACTIVE)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the rear blower switch value and it is
above 250 A/D counts.
REAR FAN POT SHORTED (ACTIVE)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the rear fan switch value and it is below
5 A/D counts.
REAR IR SENSOR HIGH (ACTIVE)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the Rear IR Sensor value and it is above
250 A/D counts.
REAR IR SENSOR LOW (ACTIVE)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the Rear IR Sensor value and it is below
5 A/D counts.
REAR MODE POT OPEN (ACTIVE)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the rear mode select switch value and it
is above 250 A/D counts.
REAR MODE POT SHORTED (ACTIVE)
When Monitored: With the ignition on and the IOD fuse installed.
Set Condition: This DTC is set if the ATC reads the rear mode select switch value and it
is below 5 A/D counts.
274
AUTOMATIC TEMPERATURE CONTROL

POSSIBLE CAUSES
REAR ATC SWITCH
TEST ACTION APPLICABILITY
1 This DTC indicates a fault in the Rear ATC Switch.
View repair.All
Repair
Replace the Rear ATC Switch.
With the DRBIIIt, reset the ATC after repair/replacement is
complete.
Perform BODY VERIFICATION TEST - VER 1.
275
AUTOMATIC TEMPERATURE CONTROL
REAR FAN POT OPEN (ACTIVE) ÐContinued

Symptom List:
B1821 COMBUSTION AIR FAN CIRCUIT: OPEN
B1821 COMBUSTION AIR FAN CIRCUIT: SHORT TO GROUND
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be B1821 COMBUSTION AIR FAN
CIRCUIT: OPEN.
When Monitored and Set Condition:
B1821 COMBUSTION AIR FAN CIRCUIT: OPEN
When Monitored: After DCHA activation, when the system is in a steady state of
operation.
Set Condition: This DTC will set if the DCHA Control detects no-load voltage on the
Combustion Air Fan circuit output pin.
B1821 COMBUSTION AIR FAN CIRCUIT: SHORT TO GROUND
When Monitored: After DCHA activation, when the system is in a steady state of
operation.
Set Condition: This DTC will set if the DCHA Control detects a high current draw on the
Combustion Air Fan circuit output pin.
POSSIBLE CAUSES
COMBUSTION AIR FAN/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 B1801 Flame Out before diag-
nosing this DTC.
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.
321
CABIN HEATER

Symptom:
B1824 FAN SWITCH LINE SHORT TO GROUND
When Monitored and Set Condition:
B1824 FAN SWITCH LINE SHORT TO GROUND
When Monitored: During DCHA activation and operation.
Set Condition: This fault is erroneous for this DCHA assembly.
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.
324
CABIN HEATER

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