2001 CHRYSLER VOYAGER engine diesel

Symptom:
P0627-FUEL LIFT PUMP RELAY CONTROL CIRCUIT SHORT CIR-
CUIT
POSSIBLE CAUSES
INTERMITTENT CONDITION
FUEL LIFT PUMP RELAY
FUEL LIFT PUMP RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, actuate the Fuel Lift Pump Relay.
Does the Fuel Lift Pump Relay cycle on and off?All
Ye s®Go To 2
No®Go To 3
2WARNING: 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.
3 Turn the ignition off.
Install a substitute relay in place of the Fuel Lift Pump Relay.
Turn the ignition on.
With the DRB, actuate the Fuel Lift Pump Relay.
Does the Fuel Lift Pump Relay cycle on and off?All
Ye s®Replace the Fuel Lift Pump Relay.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 4
131
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
4 Turn the ignition off.
Remove the Fuel Lift Pump Relay from the IPM.
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 Fuel Lift Pump Relay Control circuit.
Is the voltage below 1.0 volt?All
Ye s®Go To 5
No®Repair the Fuel Lift Pump Relay Control circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
5 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.
132
DRIVEABILITY - DIESEL
P0627-FUEL LIFT PUMP RELAY CONTROL CIRCUIT SHORT CIRCUIT Ð
Continued

Symptom List:
P0641-SENSOR REFERENCE VOLTAGE A CKT VOLTAGE TOO
HIGH
P0651-SENSOR REFERENCE VOLTAGE B CKT VOLTAGE TOO
HIGH
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 HIGH.
When Monitored and Set Condition:
P0641-SENSOR REFERENCE VOLTAGE A CKT VOLTAGE TOO HIGH
When Monitored: With the ignition on.
Set Condition: The ECM detects a short to voltage on the Sensor Reference Voltage A
circuit.
P0651-SENSOR REFERENCE VOLTAGE B CKT VOLTAGE TOO HIGH
When Monitored: With the ignition on.
Set Condition: The ECM detects a short to voltage on the Sensor Reference Voltage B
circuit.
POSSIBLE CAUSES
INTERMITTENT CONDITION
SENSOR REFERENCE VOLTAGE A OR 5-VOLT CIRCUIT SHORTED TO VOLTAGE
SENSOR REFERENCE VOLTAGE B OR 5-VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
FUEL PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
ACCELERATOR PEDAL POSITION SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
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 7
133
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the MAF Sensor harness connector.
Disconnect the ECM harness connectors.
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 on the Sensor Reference Voltage A and MAF 5-Volt Supply
circuits.
Is the voltage above 1.0 volt on either circuit?All
Ye s®Repair the Sensor Reference Voltage A or MAF 5-Volt Supply
circuit that measured above 1.0 volt for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 3
NOTE: Remove the jumper wire and reinstall the ECM/PCM Relay.
3 Turn the ignition off.
Disconnect the Boost Pressure Sensor harness connector.
Disconnect the A/C Pressure Sensor harness connector.
Disconnect the Engine Oil Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
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 on the Sensor Reference Voltage B, Boost Pressure Sensor 5-Volt
Supply, A/C Pressure Sensor 5-Volt Supply and Engine Oil Pressure Sensor 5-Volt
Supply circuits.
Is the voltage above 1.0 volt on any of the circuits?All
Ye s®Repair the Sensor Reference Voltage B or the 5-Volt Supply circuit
that measured above 1.0 volt for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 4
NOTE: Remove the jumper wire and reinstall the ECM/PCM Relay.
4 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
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 on the Fuel Pressure Sensor 5-Volt Supply circuit.
Is the voltage below 1.0 volt?All
Ye s®Go To 5
No®Repair the Fuel Pressure Sensor 5-Volt Supply circuit for a short
to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
NOTE: Remove the jumper wire and reinstall the ECM/PCM Relay.
134
DRIVEABILITY - DIESEL
P0641-SENSOR REFERENCE VOLTAGE A CKT VOLTAGE TOO HIGH Ð
Continued

TEST ACTION APPLICABILITY
5 Turn the ignition off.
Disconnect the Accelerator Pedal Position Sensor harness connector.
Disconnect the ECM harness connectors.
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 on the Accelerator Pedal Position Sensor 5-Volt Supply circuit.
Is the voltage below 1.0 volt?All
Ye s®Go To 6
No®Repair the Accelerator Pedal Position Sensor 5-Volt Supply circuit
for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
NOTE: Remove the jumper wire and reinstall the ECM/PCM Relay.
6 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.
7WARNING: 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.
135
DRIVEABILITY - DIESEL
P0641-SENSOR REFERENCE VOLTAGE A CKT VOLTAGE TOO HIGH Ð
Continued

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