engine CHRYSLER VOYAGER 2001 Service Manual

Symptom List:
P0641-SENSOR REFERENCE VOLTAGE A CKT VOLTAGE TOO LOW
P0651-SENSOR REFERENCE VOLTAGE B CKT VOLTAGE TOO LOW
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0641-SENSOR REFERENCE
VOLTAGE A CKT VOLTAGE TOO LOW.
When Monitored and Set Condition:
P0641-SENSOR REFERENCE VOLTAGE A CKT VOLTAGE TOO LOW
When Monitored: With the ignition on.
Set Condition: The ECM detects an open or short to ground on the Sensor Reference
Voltage A circuit.
P0651-SENSOR REFERENCE VOLTAGE B CKT VOLTAGE TOO LOW
When Monitored: With the ignition on.
Set Condition: The ECM detects an open or short to ground on the Sensor Reference
Voltage B circuit.
POSSIBLE CAUSES
INTERMITTENT CONDITION
MAF, OIL PRESS, BOOST PRESS, A/C PRESS, APP OR FUEL PRESS SENSOR SHORT TO
GROUND
SENSOR REFERENCE VOLTAGE OR 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
SENSOR REFERENCE VOLTAGE OR 5-VOLT SUPPLY CIRCUIT SHORTED TO SENSOR
GROUND
5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
5-VOLT SUPPLY CIRCUIT SHORTED TO SENSOR GROUND
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, erase ECM DTCs.
Monitor the DRB for ECM DTCs.
Did this DTC reset?All
Ye s®Go To 2
No®Go To 8
136
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
2 Turn the ignition on.
With the DRBIIItin Sensors, monitor the MAF, Oil Pressure, Boost Pressure, A/C
Pressure, APP and Fuel Pressure Sensors.
NOTE: If any sensor reading is above zero before disconnecting, it is not
necessary to disconnect it for this test.
One at a time while monitoring the DRB sensor readings, disconnect the MAF, Oil
Pressure, Boost Pressure, A/C Pressure, APP and Fuel Pressure Sensor harness
connectors.
NOTE: If one of the sensors is shorted to ground internally, disconnecting it
will cause the voltage reading on the DRB to rise for all sensors.
Did the DRB sensor voltage readings rise?All
Ye s®Replace the Sensor that, when disconnected, caused the DRB
sensor readings to rise.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 3
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the MAF Sensor harness connector.
Measure the resistance between ground and the Sensor Reference Voltage A circuit,
then ground and the MAF Sensor 5-Volt Supply circuit.
Disconnect the Boost Pressure Sensor, Engine Oil Pressure Sensor, and A/C Pressure
Sensor harness connectors.
Measure the resistance between ground and the Sensor Reference Voltage B circuit,
then ground and the 5-Volt Supply circuits to the Boost Pressure Sensor, A/C
Pressure Sensor and Engine Oil Pressure Sensor.
Is the resistance above 100k ohms for all of the measurements?All
Ye s®Go To 4
No®Repair the Sensor Reference Voltage or 5-Volt Supply circuit that
measured less than 100k ohms for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the MAF Sensor harness connector.
Measure the resistance between the Sensor Reference Voltage A circuit and the MAF
Sensor Ground circuit.
Disconnect the Boost Pressure Sensor, Engine Oil Pressure Sensor, and A/C Pressure
Sensor harness connectors.
Measure the resistance between the Sensor Reference Voltage B circuit and the Boost
Pressure Sensor Ground circuit, then the A/C Pressure Sensor Ground circuit, and
finally the Engine Oil Pressure Sensor Ground circuit.
Is the resistance above 100k ohms for all measurements?All
Ye s®Go To 5
No®Repair the Sensor Reference Voltage or 5-Volt Supply circuit that
measured less than 100k ohms for a short to the Sensor Ground
circuit.
Perform ROAD TEST VERIFICATION - VER-2.
137
DRIVEABILITY - DIESEL
P0641-SENSOR REFERENCE VOLTAGE A CKT VOLTAGE TOO LOW Ð
Continued

TEST ACTION APPLICABILITY
5 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Fuel Pressure Sensor harness connector.
Measure the resistance between ground and the Fuel Pressure Sensor 5-Volt Supply
circuit.
Disconnect the Accelerator Pedal Position Sensor harness connector.
Measure the resistance between ground and the Accelerator Pedal Position Sensor
5-Volt Supply circuit.
Is the resistance above 100k ohms for each measurement?All
Ye s®Go To 6
No®Repair the 5-Volt Supply circuit(s) that measured less than 100k
ohms for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
6 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Fuel Pressure Sensor harness connector.
Measure the resistance between the Fuel Pressure Sensor 5-Volt Supply circuit and
the Sensor Ground circuit.
Disconnect the Accelerator Pedal Position Sensor harness connector.
Measure the resistance between the Accelerator Pedal Position Sensor 5-Volt Supply
circuit and the Sensor Ground circuit.
Is the resistance above 100k ohms for each measurement?All
Ye s®Go To 7
No®Repair the 5-Volt Supply circuit(s) that measured less than 100k
ohms for a short to the Sensor Ground circuit.
Perform ROAD TEST VERIFICATION - VER-2.
7 If there are no possible causes remaining, view repair. All
Repair
Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
8WARNING: 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, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the
conditions under which the DTC was set.
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 ROAD TEST VERIFICATION - VER-2.
No®Test Complete.
138
DRIVEABILITY - DIESEL
P0641-SENSOR REFERENCE VOLTAGE A CKT VOLTAGE TOO LOW Ð
Continued

TEST ACTION APPLICABILITY
3WARNING: KEEP CLEAR OF THE ENGINE'S MOVING PARTS.
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, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
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 ROAD TEST VERIFICATION - VER-2.
No®Test Complete.
4 Turn the ignition off.
Remove the A/C Clutch Relay from the IPM.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Fused Ignition Switch
circuit in the IPM.
Does the test light illuminate?All
Ye s®Go To 5
No®Go To 10
5 Turn the ignition off.
Remove the A/C Clutch Relay from the IPM.
Turn the ignition on.
Using a 12-volt test light connected to 12-volts, probe the A/C Clutch Relay Control
circuit in the IPM.
With the DRBIIIt, actuate the A/C Clutch Relay.
Does the test light cycle on and off?All
Ye s®Replace the A/C Clutch Relay.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 6
6 Turn the ignition off.
Disconnect the Intelligent Power Module C3 harness connector.
Turn the ignition on.
Using a 12-volt test light connected to 12-volts, probe the A/C Clutch Relay Control
circuit in the IPM harness connector.
With the DRBIIIt, actuate the A/C Clutch Relay.
Does the test light flash on and off?All
Ye s®Replace the IPM Fused & Relay Center.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 7
140
DRIVEABILITY - DIESEL
P0645-A/C CLUTCH RELAY CIRCUIT OPEN CIRCUIT ÐContinued

TEST ACTION APPLICABILITY
7 Turn the ignition off.
Disconnect the Intelligent Power Module C3 harness connector.
Disconnect the ECM harness connector.
Measure the resistance of the A/C Clutch Relay Control circuit between the
Intelligent Power Module C3 harness connector and the ECM harness connector.
Is the resistance below 5.0 ohms.All
Ye s®Go To 8
No®Repair the A/C Clutch Relay Control circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
8 Turn the ignition off.
Disconnect the Intelligent Power Module C3 harness connector.
Disconnect the ECM harness connector.
Measure the resistance of the A/C Clutch Relay Control circuit in the Intelligent
Power Module C3 harness connector to ground.
Is the resistance below 5.0 ohms.All
Ye s®Repair the A/C Clutch Relay Control circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 9
9 If there are no possible causes remaining, view repair. All
Repair
Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
10 Turn the ignition off.
Disconnect the Intelligent Power Module C3 harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Fused Ignition Switch
circuit in the IPM harness connector.
Does the test light illuminate?All
Ye s®Replace the IPM Fuse & Relay Center.
Perform ROAD TEST VERIFICATION - VER-2.
No®Repair the Fused Ignition Switch Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
141
DRIVEABILITY - DIESEL
P0645-A/C CLUTCH RELAY CIRCUIT OPEN CIRCUIT ÐContinued

TEST ACTION APPLICABILITY
3WARNING: KEEP CLEAR OF THE ENGINE'S MOVING PARTS.
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, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
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 ROAD TEST VERIFICATION - VER-2.
No®Test Complete.
4 Turn the ignition off.
Remove the A/C Clutch Relay from the IPM.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Fused Ignition Switch
circuit in the IPM.
Does the test light illuminate?All
Ye s®Go To 5
No®Go To 9
5 Turn the ignition off.
Remove the A/C Clutch Relay from the IPM.
Turn the ignition on.
Using a 12-volt test light connected to 12-volts, probe the A/C Clutch Relay Control
circuit in the IPM.
With the DRBIIIt, actuate the A/C Clutch Relay.
Does the test light cycle on and off?All
Ye s®Replace the A/C Clutch Relay.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 6
6 Turn the ignition off.
Disconnect the Intelligent Power Module C3 harness connector.
Turn the ignition on.
Using a 12-volt test light connected to 12-volts, probe the A/C Clutch Relay Control
circuit in the IPM harness connector.
With the DRBIIIt, actuate the A/C Clutch Relay.
Does the test light flash on and off?All
Ye s®Replace the IPM Fused & Relay Center.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 7
143
DRIVEABILITY - DIESEL
P0645-A/C CLUTCH RELAY CIRCUIT SHORT CIRCUIT ÐContinued

TEST ACTION APPLICABILITY
7 Turn the ignition off.
Disconnect the Intelligent Power Module C3 harness connector.
Disconnect the ECM harness connector.
Remove the ECM/PCM Relay from the IPM.
Connect a jumper wire between cavity 30 and cavity 87 of the ECM/PCM Relay
connector.
Turn the ignition on.
Measure the voltage of the A/C Clutch Relay Control circuit.
Is the voltage above 1.0 volt?All
Ye s®Repair the A/C Clutch Relay Control circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 8
8 If there are no possible causes remaining, view repair. All
Repair
Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
9 Turn the ignition off.
Disconnect the Intelligent Power Module C3 harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Fused Ignition Switch
circuit in the IPM harness connector.
Does the test light illuminate?All
Ye s®Replace the IPM Fuse & Relay Center.
Perform ROAD TEST VERIFICATION - VER-2.
No®Repair the Fused Ignition Switch Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
144
DRIVEABILITY - DIESEL
P0645-A/C CLUTCH RELAY CIRCUIT SHORT CIRCUIT ÐContinued

Symptom:
P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO
EARLY
When Monitored and Set Condition:
P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO EARLY
When Monitored: During after-run.
Set Condition: The internal ECM timer determines that the ECM/PCM Relay has shut
off before the AFTER-RUN mode of operation has been completed.
POSSIBLE CAUSES
CHECK FOR OTHER DTCS
INTERMITTENT CONDITION
SUBSTITUTE ECM/PCM RELAY
ECM/PCM RELAY CONTROL CIRCUIT OPEN INTERMITTENTLY
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, check for additional DTCs.
Are other DTCs present?All
Ye s®Refer to the Symptom List for diagnosis of the other DTCs before
continuing.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 2
2 Turn the ignition on.
With the DRB, erase ECM DTCs.
Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC reset?All
Ye s®Go To 3
No®Go To 5
145
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Install a substitute relay in place of the ECM/PCM Relay.
Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC reset?All
Ye s®Go To 4
No®Replace the ECM/PCM Relay.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Remove the ECM/PCM Relay from the IPM.
Disconnect the ECM harness connectors.
Measure the resistance of the ECM/PCM Relay Control circuit while wiggling the
wiring harness and connectors between the ECM and the IPM.
Was the resistance above 5.0 ohms at any time while wiggling the wiring harness and
connectors?All
Ye s®Repair the ECM/PCM Relay Control circuit for an intermittent
open.
Perform ROAD TEST VERIFICATION - VER-2.
No®Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
5WARNING: 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, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the
conditions under which the DTC was set.
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 ROAD TEST VERIFICATION - VER-2.
No®Test Complete.
146
DRIVEABILITY - DIESEL
P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO EARLY Ð
Continued

Symptom:
P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO
LATE
When Monitored and Set Condition:
P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO LATE
When Monitored: During after-run.
Set Condition: The internal ECM timer determines that the ECM/PCM Relay remains on
too long when AFTER-RUN mode of operation has been completed.
POSSIBLE CAUSES
CHECK FOR OTHER DTCS
INTERMITTENT CONDITION
SUBSTITUTE ECM/PCM RELAY
ECM/PCM RELAY CONTROL CIRCUIT SHORTED TO GROUND INTERMITTENTLY
ECM/PCM RELAY OUTPUT CIRCUIT SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, check for additional DTCs.
Are other DTCs present?All
Ye s®Refer to the Symptom List for diagnosis of the other DTCs before
continuing.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 2
2 Turn the ignition on.
With the DRB, erase ECM DTCs.
Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC reset?All
Ye s®Go To 3
No®Go To 6
147
DRIVEABILITY - DIESEL