heater CHRYSLER VOYAGER 2001 Repair Manual

Symptom:
FCM, HVAC COMMUNICATION FAULT
When Monitored and Set Condition:
FCM, HVAC COMMUNICATION FAULT
When Monitored: With the ignition in run, and the IOD fuse installed.
Set Condition: The FCM does not receive any messages from the Automatic Temperature
Control (ATC) module or the A/C Heater Control (MTC) for at least 20 seconds.
POSSIBLE CAUSES
ATTEMPT TO COMMUNICATE WITH THE HVAC
FRONT CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, attempt to communicate with the A/C Heater Control (MTC) or the
Automatic Temp Control (ATC).
Was the DRB able to I/D or communicate with the HVAC or the ATC?All
Ye s®Go To 2
No®Refer to the Communication category for the related symptom(s).
Perform BODY VERIFICATION TEST - VER 1.
2 With the DRB, erase DTC's.
Cycle the ignition switch from off to on and wait approximately 1 minute.
With the DRB, read DTC's.
Did this DTC reset?All
Ye s®Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Test Complete.
345
COMMUNICATION

Symptom:
*BUS +/- SIGNALS OPEN OR NO RESPONSE FROM HVAC
POSSIBLE CAUSES
ATTEMPT TO COMMUNICATE WITH THE BCM
GROUND CIRCUIT OPEN
IGNITION SWITCH CIRCUIT OPEN
OPEN PCI BUS CIRCUIT
A/C HEATER CONTROL
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, enter Body then Body Computer.
Was the DRB able to I/D or communicate with the BCM?All
Ye s®Go To 2
No®Refer to the symptom list for problems related to no communica-
tion with the BCM.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance between ground and the ground circuit.
Is the resistance below 5.0 ohms?All
Ye s®Go To 3
No®Repair the Ground circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Ignition Switch circuit.
Is the test light illuminated?All
Ye s®Go To 4
No®Repair the Ignition Switch circuit for an open or short.
Perform BODY VERIFICATION TEST - VER 1.
381
COMMUNICATION

TEST ACTION APPLICABILITY
4Note: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Disconnect the A/C Heater Control C1 harness connector.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
Select DRB Standalone.
Select lab scope.
Select Live Data.
Select 12 volt square wave.
Press F2 for Scope.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the A/C Heater Control connector.
Turn the ignition on.
Observe the voltage display on the DRB Lab Scope.
Does the voltage pulse from 0 to approximately 7.5 volts?All
Ye s®Go To 5
No®Repair the PCI Bus circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
5 If there are no possible causes remaining, view repair. All
Repair
Replace the A/C Heater Control.
Perform BODY VERIFICATION TEST - VER 1.
382
COMMUNICATION
*BUS +/- SIGNALS OPEN OR NO RESPONSE FROM HVAC ÐContinued

Symptom:
*NO RESPONSE FROM CABIN HEATER ASSIST - DIESEL ONLY
POSSIBLE CAUSES
ATTEMPT TO COMMUNICATE WITH THE ECM
FUSED B+ CIRCUIT OPEN
GROUND CIRCUIT OPEN
SCI TRANSMIT CIRCUIT OPEN
CABIN HEATER ASSIST
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, attempt to communicate with the ECM.
Was the DRB able to I/D or communicate with the ECM?All
Ye s®Go To 2
No®Refer to the symptom list for problems related to no communica-
tion with the ECM.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Disconnect the Cabin Heater Assist C2 harness connector.
Using a 12-volt test light connected to ground, probe the Fused B+ circuit.
Is the test light illuminated?All
Ye s®Go To 3
No®Check the IPM Fuse #15 for an open. If open, check for a short to
ground on the Fused B+ circuit. If not open, repair the Fused B+
circuit for an open.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the Cabin Heater Assist C2 harness connector.
Measure the resistance between ground and the ground circuit.
Is the resistance below 5.0 ohms?All
Ye s®Go To 4
No®Repair the ground circuit for an open.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
4 Turn the ignition off.
Disconnect the Cabin Heater Assist C1 harness connector.
Disconnect the DRB from the DLC.
Measure the resistance of the SCI Transmit circuit between the Cabin Heater Assist
connector and the DLC.
Is the resistance below 5.0 ohms?All
Ye s®Go To 5
No®Repair the SCI Transmit circuit for an open.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
397
COMMUNICATION

TEST ACTION APPLICABILITY
5 If there are no possible causes remaining, view repair. All
Repair
Replace the Cabin Heater Assist in accordance with the service
information.
Perform CABIN HEATER VERIFICATION TEST - VER 1.
398
COMMUNICATION
*NO RESPONSE FROM CABIN HEATER ASSIST - DIESEL ONLY Ð
Continued

Symptom:
*NO RESPONSE FROM ECM (SCI ONLY) - DIESEL ONLY
POSSIBLE CAUSES
CHECK ECM POWERS AND GROUNDS
CABIN HEATER ASSIST
SCI TRANSMIT CIRCUIT SHORTED TO VOLTAGE
SCI TRANSMIT CIRCUIT SHORTED TO GROUND
SCI TRANSMIT CIRCUIT OPEN
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 Perform the symptom Checking ECM Power and Ground Circuits in the Driveability
category.
Did the vehicle pass this test?All
Ye s®Go To 2
No®Repair as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the DRB from the DLC.
Measure the resistance between ground and the SCI Transmit circuit.
Is the resistance below 5.0 ohms?All
Ye s®Go To 3
No®Go To 4
3 Turn the ignition off.
Disconnect the Cabin Heater Assist C1 harness connector.
Measure the resistance between ground and the SCI Transmit circuit.
Is the resistance below 5.0 ohms?All
Ye s®Repair the SCI Transmit circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No®Replace the Cabin Heater Assist in accordance with the service
information.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the DRB from the DLC.
Disconnect the ECM harness connectors.
Disconnect the Cabin Heater Assist C1 harness connector.
Turn the ignition on.
Measure the voltage of the SCI Transmit circuit at the DLC connector (cav 7).
Is the voltage above 1.0 volt?All
Ye s®Repair the SCI Transmit circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 5
402
COMMUNICATION

Symptom List:
A/C FAULT (ACTIVE) - MANUAL A/C
CHECKSUM FAILURE (ACTIVE) - MANUAL A/C
POWER FAULT (ACTIVE) - MANUAL A/C
REAR DEFOG FAILURE (ACTIVE) - MAN A/C
RECIRCULATION FAULT (ACTIVE) - MANUAL A/C
UNKNOWN FAULT DETECTED (ACTIVE) - MANUAL A/C
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be A/C FAULT (ACTIVE) - MANUAL
A/C.
When Monitored and Set Condition:
A/C FAULT (ACTIVE) - MANUAL A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the A/C switch stays closed for 10 minutes.
CHECKSUM FAILURE (ACTIVE) - MANUAL A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the calibrated check sum does not match the stored
value.
POWER FAULT (ACTIVE) - MANUAL A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Power switch stays closed for 10 minutes.
REAR DEFOG FAILURE (ACTIVE) - MAN A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Rear Window Defogger switch stays closed for 10
minutes.
RECIRCULATION FAULT (ACTIVE) - MANUAL A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Recirc switch stays closed for 10 minutes.
UNKNOWN FAULT DETECTED (ACTIVE) - MANUAL A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the A/C - Heater Cotrol Module detects an internal
fault.
512
HEATING & A/C

POSSIBLE CAUSES
A/C - HEATER CONTROL MODULE
TEST ACTION APPLICABILITY
1 View repairAll
Repair
Replace the A/C - Heater Control Module in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
513
HEATING & A/C
A/C FAULT (ACTIVE) - MANUAL A/C ÐContinued

Symptom List:
A/C FAULT (STORED) - MANUAL A/C
BACKLIGHT DIMMING RX FAILURE (STORED) - MANUAL A/C
BLEND OVERCURRENT (STORED) - MANUAL A/C
CHECKSUM FAILURE (STORED) - MANUAL A/C
EVAPORATOR TEMPERATURE SENSOR CIRCUIT OPEN
(STORED) - MANUAL A/C
EVAPORATOR TEMPERATURE SENSOR CIRCUIT SHORT
(STORED) - MANUAL A/C
LOOPBACK FAILURE (STORED) - MANUAL A/C
LOOPBACK TEST FAILURE (STORED) - MANUAL A/C
MODE OVERCURRENT (STORED) - MANUAL A/C
NO BCM MESSAGE RECEIVED (STORED) - MANUAL A/C
NO PCM MESSAGE RECEIVED (STORED) - MANUAL A/C
PCM COMMUNICATION FAILURE (STORED) - MANUAL A/C
POWER FAULT (STORED) - MANUAL A/C
REAR BLEND OVERCURRENT (STORED) - MANUAL A/C
REAR BLEND POT CIRCUIT OPEN (STORED) - MANUAL A/C
REAR BLEND POT CIRCUIT SHORT (STORED) - MANUAL A/C
REAR DEFOG FAILURE (STORED) - MANUAL A/C
REAR MODE OVERCURRENT (STORED) - MANUAL A/C
RECIRC OVERCURRENT (STORED) - MANUAL A/C
RECIRCULATION FAULT (STORED) - MANUAL A/C
TX FAILURE (STORED) - MANUAL A/C
UNKNOWN FAULT DETECTED (STORED) - MANUAL A/C
VEHICLE ODOMETER FAILURE (STORED) - MANUAL A/C
ZONE OVERCURRENT (STORED) - MANUAL A/C
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be A/C FAULT (STORED) - MANUAL
A/C.
When Monitored and Set Condition:
A/C FAULT (STORED) - MANUAL A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the A/C switch stays closed for 10 minutes.
BACKLIGHT DIMMING RX FAILURE (STORED) - MANUAL A/C
When Monitored: With the ignition on.
Set Condition: If the A/C - Heater Control Module does not receive the dimming function
message from the BCM for more than 5 seconds, then the A/C - Heater Control Module
LEDs will default to full brightness and the DTC will set.
514
HEATING & A/C

BLEND OVERCURRENT (STORED) - MANUAL A/C
When Monitored: When actuator movement is requested.
Set Condition: All (Blend, Mode, Recirc, and Zone) Overcurrent DTCs will set if the A/C
- Heater Control Module detects an excessive current draw on the Common Door Drive
circuit(s).
CHECKSUM FAILURE (STORED) - MANUAL A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the calibrated check sum does not match the stored
value.
EVAPORATOR TEMPERATURE SENSOR CIRCUIT OPEN (STORED) - MANUAL
A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Evaporator Temperature Sensor/sensor circuit is
open.
EVAPORATOR TEMPERATURE SENSOR CIRCUIT SHORT (STORED) - MAN-
UAL A/C
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Evaporator Temperature Sensor/sensor circuit is
shorted low.
LOOPBACK FAILURE (STORED) - MANUAL A/C
When Monitored: When the A/C - Heater Control Module executes an internal loopback
test.
Set Condition: If the A/C - Heater Control Module fails to send a message, or none of the
expected messages arrive for 5 seconds, an internal loopback test is executed. If the
internal loopback test fails, the DTC will set.
LOOPBACK TEST FAILURE (STORED) - MANUAL A/C
When Monitored: When the A/C - Heater Control Module executes an internal loopback
test.
Set Condition: If the A/C - Heater Control Module fails to send a message, or none of the
expected messages arrive for 5 seconds, an internal loopback test is executed. If the
internal loopback test fails, the DTC will set.
MODE OVERCURRENT (STORED) - MANUAL A/C
When Monitored: When actuator movement is requested.
Set Condition: All (Blend, Mode, Recirc, and Zone) Overcurrent DTCs will set if the A/C
- Heater Control Module detects an excessive current draw on the Common Door Drive
circuit(s).
515
HEATING & A/C
A/C FAULT (STORED) - MANUAL A/C ÐContinued