2001 CHRYSLER VOYAGER air condition

Symptom:
FCM, PCM COMMUNICATION FAULT
When Monitored and Set Condition:
FCM, PCM 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 PCM for at least 5
seconds.
POSSIBLE CAUSES
PCM COMMUNICATION FAULT
ATTEMPT TO COMMUNICATE WITH THE PCM
PCI BUS CIRCUIT OPEN
POWERTRAIN CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, enter Instrument Cluster, System Tests then PCM Monitor.
Does the DRB display: PCM is active on BUS?All
Ye s®Erase the DTC, if DTC resets, replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 2
2 Turn the ignition on.
With the DRB, attempt to communicate with the PCM.
Was the DRB able to communicate with the PCM?All
Ye s®Go To 3
No®Refer to the communication category and perform the appropriate
symptom.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the PCM C2 harness connector.
Connect the diagnostic junction port tester #8339 to the diagnostic junction port.
Note: Do not connect the tester to the DRB.
Measure the resistance of the PCI Bus circuit between the diagnostic junction port
tester and the PCM C2 connector.
Is the resistance below 5.0 ohms?All
Ye s®Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No®Repair the PCI Bus circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
347
COMMUNICATION

Symptom:
IGNITION MUX SWITCH INPUT OPEN
When Monitored and Set Condition:
IGNITION MUX SWITCH INPUT OPEN
When Monitored: With the ignition on and battery voltage greater than 10.4 volts.
Set Condition: The Ignition MUX sense circuit voltage at the BCM goes above 4.9 volts.
POSSIBLE CAUSES
IGNITION SWITCH
IGNITION SWITCH SENSE CIRCUIT OPEN
IGNITION SWITCH SENSE RETURN CIRCUIT OPEN
BODY CONTROL MODULE
BODY CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the ignition switch 5-way connector.
Connect a jumper wire between the Ignition Switch Sense circuit and ground.
With the DRBIIItin Sensors, read the IGNITION SW voltage.
Does the DRBIIItdisplay IGNITION SW 0.0 volts?All
Ye s®Go To 2
No®Go To 3
2 Turn the ignition off.
Gain access to the Body Control Module C5 connector.
Backprobe a jumper wire between the Ignition Switch Sense circuit and ground.
With the DRBIIItin Sensors, read the IGNITION SW voltage.
Does the DRBIIItdisplay IGNITION SW 0.0 volts?All
Ye s®Repair the Ignition Switch Sense circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the ignition switch connector.
Connect a jumper wire between the Ignition Switch Sense circuit and the Ignition
Switch Sense Return circuit.
With the DRBIIItin Sensors, read the IGNITION SW voltage.
Does the DRBIIItdisplay IGNITION SW 0.0 volts?All
Ye s®Replace the Ignition Switch.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 4
350
COMMUNICATION

Symptom:
IGNITION MUX SWITCH INPUT SHORT
When Monitored and Set Condition:
IGNITION MUX SWITCH INPUT SHORT
When Monitored: With the ignition on and battery voltage greater than 10.4 volts.
Set Condition: The Ignition MUX Sense circuit voltage at the BCM goes below 0.5 volt for
more than 2 seconds.
POSSIBLE CAUSES
IGNITION SWITCH SENSE CIRCUIT SHORTED
IGNITION SWITCH SENSE RETURN CIRCUIT OPEN
IGNITION SWITCH SHORTED
BODY CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the ignition switch 5-way connector.
With the DRBIIItin Sensors, read the IGNITION SW voltage.
Does the DRBIIItdisplay IGNITION SW 0.0 volts?All
Ye s®Go To 2
No®Replace the Ignition Switch.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Gain access to the Body Control Module.
Disconnect the Body Control Module C5 connector.
Measure the resistance of the Ignition Switch Sense circuit in the BCM C5 connector.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Ignition Switch Sense circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 3
3 Turn the ignition off.
Gain access to the Body Control Module.
Disconnect the Body Control Module C4 connector.
Measure the resistance of the Ignition Switch Sense Return circuit in the BCM C4
connector.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Ignition Switch Sense Return circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
352
COMMUNICATION

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the HVAC connector.
Turn the ignition on.
Measure the voltage of the Ignition Switch Run (HVAC) circuit in the HVAC
controller connector.
Is the voltage above 10.0 volts?All
Ye s®Go To Test #6. The condition that caused the DTC to set is not
present on this circuit. Further diagnostics are required to
determine the cause of the DTC.
No®Go To 4
4 Gain access to the Body Control Module C4 connector.
Turn the ignition on.
While back probing, measure the voltage of the Ignition Switch Run (HVAC) circuit.
Is the voltage above 10.0 volts?All
Ye s®Repair the Ignition Switch Run (HVAC) circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 5
5 Turn the ignition off.
Disconnect the Body Control Module C4 connector.
Measure the resistance between ground and the Ignition Switch Run (HVAC) circuit
in the HVAC controller connector.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Ignition Switch Run (HVAC) circuit for a short to
ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 6
6 A failure in the HVAC, Overhead Console, or the ABS system could cause this DTC
to set. The Ignition Switch Output (Overhead Console) circuit will be diagnosed.
Continue to the OVERHEAD CONSOLE circuit for further diagnosis.All
OVERHEAD CONSOLE circuit diagnostics.
Go To 7
7 Turn the ignition off.
Disconnect the Overhead Console connector.
Turn the ignition on.
Measure the voltage of the Ignition Switch Output circuit in the Overhead Console
connector.
Is the voltage above 10.0 volts?All
Ye s®Go To Test #10. The condition that caused the DTC to set is not
present on this circuit. Further diagnostics are required to
determine the cause of the DTC.
No®Go To 8
354
COMMUNICATION
IGNITION RUN OUTPUT SHORT ÐContinued

TEST ACTION APPLICABILITY
8 Gain access to the Body Control Module C3 connector.
Turn the ignition on.
While back probing, measure the voltage of the Ignition Switch Output circuit.
Is the voltage above 10.0 volts?All
Ye s®Repair the Ignition Switch Output circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 9
9 Turn the ignition off.
Disconnect the Body Control Module C3 connector.
Measure the resistance between ground and the Ignition Switch Output circuit in the
Overhead Console connector.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Ignition Switch Output circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 10
10 A failure in the HVAC, Overhead Console, or the ABS system could cause this DTC
to set. The Fused Ignition Switch Output (ABS) circuit will be diagnosed.
Continue to the ABS circuit for further diagnosis.All
ABS circuit diagnostics.
Go To 11
11 Turn the ignition off.
Disconnect the ABS connector.
Turn the ignition on.
Measure the voltage of the Fused Ignition Switch Output circuit in the ABS
connector.
Is the voltage above 10.0 volts?All
Ye s®The condition that caused the DTC to set is not present on this
circuit. Further diagnostics are required to determine the cause of
the DTC.
No®Go To 12
12 Gain access to the Body Control Module C3 connector.
Turn the ignition on.
While back probing, measure the voltage of the Fused Ignition Switch Output circuit.
Is the voltage above 10.0 volts?All
Ye s®Repair the Ignition Switch Output circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 13
13 Turn the ignition off.
Disconnect the Body Control Module C3 connector.
Measure the resistance between ground and the Fused Ignition Switch Output
circuit in the ABS connector.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Ignition Switch Output circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 14
355
COMMUNICATION
IGNITION RUN OUTPUT SHORT ÐContinued

TEST ACTION APPLICABILITY
14 Select the diagnostic repair. All
For this condition:
Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
356
COMMUNICATION
IGNITION RUN OUTPUT SHORT ÐContinued

Symptom:
PCM MESSAGES NOT RECEIVED
When Monitored and Set Condition:
PCM MESSAGES NOT RECEIVED
When Monitored: With the ignition in run, and the IOD fuse installed.
Set Condition: The BCM does not receive any messages from the PCM for at least 5
seconds.
POSSIBLE CAUSES
PCM MESSAGE NOT RECEIVED
ATTEMPT TO COMMUNICATE WITH THE PCM
PCI BUS CIRCUIT OPEN
POWERTRAIN CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, enter Instrument Cluster, System Tests then PCM Monitor.
Does the DRB display: PCM is active on BUS?All
Ye s®Erase the DTC, if DTC resets, replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 2
2 Turn the ignition on.
With the DRB, attempt to communicate with the PCM.
Was the DRB able to communicate with the PCM?All
Ye s®Go To 3
No®Refer to the communication category and perform the appropriate
symptom.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the PCM C2 harness connector.
Connect the diagnostic junction port tester #8339 to the diagnostic junction port.
Note: Do not connect the tester to the DRB.
Measure the resistance of the PCI Bus circuit between the diagnostic junction port
tester and the PCM C2 connector.
Is the resistance below 5.0 ohms?All
Ye s®Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No®Repair the PCI Bus circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
367
COMMUNICATION

Symptom:
RUN/START HARDWIRE INPUT FAILURE
When Monitored and Set Condition:
RUN/START HARDWIRE INPUT FAILURE
When Monitored: With the ignition on and battery voltage greater than 10.4 volts.
Set Condition: The Fused Ignition Switch Output circuit voltage at the BCM goes below
0.5 volts and the BCM detects a voltage mismatch between the two ignition switch inputs.
POSSIBLE CAUSES
TEST FOR CURRENT DTC'S
FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN
IGNITION SWITCH
BODY CONTROL MODULE
TEST ACTION APPLICABILITY
1 With the DRBIIIt, record and erase DTC's.
Cycle the ignition from ON to OFF.
Start the vehicle and observe the DRBIIIt.
With the DRBIIIt, read DTC's.
Does the DRBIIItdisplay RUN/START HARDWIRE INPUT FAILURE?All
Ye s®Go To 2
No®The condition that caused this DTC is currently not present. Use
the wiring diagram/schematic as a guide, and inspect the related
wiring harness for a possible intermittent condition.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Gain access to the Ignition Switch connector.
Turn the ignition on.
While back probing, measure the voltage of the Fused Ignition Switch Output circuit.
Is the voltage above 10.0 volts?All
Ye s®Go To 3
No®Replace the Ignition Switch.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Gain access to the Body Control Module C2 connector.
While back probing, measure the voltage of the Fused Ignition Switch Output circuit.
Is the voltage above 10.0 volts?All
Ye s®Repair the Fused Ignition Switch Output circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
370
COMMUNICATION