
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the CKP Sensor harness connector.
Measure the resistance of the Shield circuit.
Is the resistance below 10.0 ohms?All
Ye s®Go To 4
No®Repair the Shield circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
4 Replace the Crankshaft Position Sensor in accordance with the Service Information.
With the DRB, erase ECM DTCs.
Perform several drive cycles, turning the ignition off for at least 10 seconds between
each drive cycle.
Monitor the DRB for ECM DTCs.
Did this DTC reset?All
Ye s®Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No®The repair is complete. Refer to the Service Information to check
for engine mechanical problems that may have occurred due to
excessive engine speed.
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.
Check the Engine Speed Sensor wiring harness for incorrect routing which may
cause EMI interference.
Were any of the above conditions present?All
Ye s®Repair as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No®Test Complete.
74
DRIVEABILITY - DIESEL
P0335-CKP POSITION SENSOR CIRCUIT OVERSPEED RECOGNITION
Ð
Continued

TEST ACTION APPLICABILITY
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.
Disconnect the Glow Plug Relay harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the ECM/PCM Relay Output
circuit.
Does the test light illuminate brightly?All
Ye s®Go To 4
No®Repair the ECM/PCM Relay Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Install a substitute relay in place of the Glow Plug 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 5
No®Replace the Glow Plug Relay.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Glow Plug Relay harness connector.
Remove the ECM/PCM Relay from the IPM.
Connect a jumper wire between cavity 1 and cavity 4 of the ECM/PCM Relay
connector.
Turn the ignition on.
Measure the voltage on the Glow Plug Relay Control circuit.
Is the voltage above 1.0 volt?All
Ye s®Repair the Glow Plug Relay Control circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 6
85
DRIVEABILITY - DIESEL
P0380-GLOW PLUG CIRCUIT A OPEN CIRCUIT ÐContinued

Symptom:
P0403-EGR SOLENOID CIRCUIT OPEN CIRCUIT
When Monitored and Set Condition:
P0403-EGR SOLENOID CIRCUIT OPEN CIRCUIT
When Monitored: With the ignition on.
Set Condition: The ECM detects an open or short to ground on the EGR Solenoid Control
circuit.
POSSIBLE CAUSES
INTERMITTENT CONDITION
ECM/PCM RELAY OUTPUT CIRCUIT OPEN
EGR SOLENOID CONTROL CIRCUIT SHORTED TO GROUND
EGR SOLENOID CONTROL CIRCUIT OPEN
SUBSTITUTE EGR SOLENOID
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, erase ECM DTCs.
Perform several ignition cycles, turning the ignition off for at least 10 seconds
between each ignition cycle.
Monitor the DRB for ECM DTCs.
Did this DTC reset?All
Ye s®Go To 2
No®Go To 7
2 Turn the ignition off.
Disconnect the EGR Solenoid harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the ECM/PCM Relay Output
circuit.
Does the test light illuminate brightly?All
Ye s®Go To 3
No®Repair the ECM/PCM Relay Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
87
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the EGR Solenoid harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the EGR Solenoid Control circuit.
Is the resistance above 100k ohms?All
Ye s®Go To 4
No®Repair the EGR Solenoid Control circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the EGR Solenoid harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the EGR Solenoid Control circuit.
Is the resistance below 5.0 ohms?All
Ye s®Go To 5
No®Repair the EGR Solenoid Control circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Install a substitute EGR Solenoid in place of the vehicle's EGR Solenoid.
NOTE: Ensure the ECM and EGR Solenoid harness connectors are con-
nected.
Turn the ignition on.
With the DRB, check for this DTC to reset.
Did this DTC reset?All
Ye s®Go To 6
No®Replace the EGR Solenoid.
Perform ROAD TEST VERIFICATION - VER-2.
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.
88
DRIVEABILITY - DIESEL
P0403-EGR SOLENOID CIRCUIT OPEN CIRCUIT ÐContinued

Symptom:
P0403-EGR SOLENOID CIRCUIT SHORT CIRCUIT
When Monitored and Set Condition:
P0403-EGR SOLENOID CIRCUIT SHORT CIRCUIT
When Monitored: With the ignition on.
Set Condition: The ECM detects excessive current draw on the EGR Solenoid Control
circuit.
POSSIBLE CAUSES
INTERMITTENT CONDITION
EGR SOLENOID
EGR SOLENOID CONTROL SHORTED TO VOLTAGE
ENGINE CONTROL MODULE - INTERNAL
ENGINE CONTROL MODULE - INTERNAL SHORT TO VOLTAGE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, erase ECM DTCs.
Test drive the vehicle and monitor the DRB for ECM DTCs.
Did this DTC reset?All
Ye s®Go To 2
No®Go To 5
2 Turn the ignition off.
Disconnect the EGR Solenoid harness connector.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Monitor the DRB for ECM DTCs.
Does the DRB display P0403 EGR OPEN CIRCUIT?All
Ye s®Replace the EGR Solenoid.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 3
3 Turn the ignition off.
Disconnect the EGR Solenoid harness connector.
Turn the ignition on.
Measure the voltage of the EGR Solenoid Control circuit at the EGR Solenoid
harness connector.
Is the voltage below 0.5 volt?All
Ye s®Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 4
90
DRIVEABILITY - DIESEL

Symptom:
P0520- OIL PRESS SENSOR CIRCUIT MALF PLAUSIBILITY
When Monitored and Set Condition:
P0520- OIL PRESS SENSOR CIRCUIT MALF PLAUSIBILITY
When Monitored: At engine start-up.
Set Condition: The oil pressure signal is below the lower limit for four seconds after
engine start-up.
POSSIBLE CAUSES
5-VOLT SUPPLY CIRCUIT OPEN
ECM - OIL PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
ECM - OIL PRESSURE SENSOR SIGNAL SHORT TO GROUND
INCORRECT OIL PRESSURE
OIL PRESSURE SENSOR FAILURE
OIL PRESSURE SENSOR SIGNAL CIRCUIT OPEN
OIL PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
OIL PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO SENSOR GROUND
OIL PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
SENSOR GROUND CIRCUIT OPEN
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1NOTE: If DTC P0641 or P0651 is present with this DTC, diagnose these
DTC's before diagnosing this DTC.
Turn the ignition on.
With the DRB III, erase ECM DTCs.
Cycle the ignition key on and off several times, leaving the key on for at least 10
seconds at a time.
Test drive the vehicle.
With the DRB III, read ECM DTCs.
Did this DTC reset?All
Ye s®Go To 2
No®Go To 10
2 Refer to the Service Information and perform the Oil Pressure Test.
Is the oil pressure within specification?All
Ye s®Go To 3
No®Repair as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
107
DRIVEABILITY - DIESEL

Symptom:
P0520-OIL PRESS SENSOR CKT MALF SUPPLY VOLTAGE TOO
HIGH OR LOW
When Monitored and Set Condition:
P0520-OIL PRESS SENSOR CKT MALF SUPPLY VOLTAGE TOO HIGH OR LOW
When Monitored: With the ignition on.
Set Condition: The Sensor Reference Voltage9A9voltage to the Oil Pressure Sensor is
below 4.8 volts or above 5.2 volts for at least 100 ms.
POSSIBLE CAUSES
INTERMITTENT CONDITION
5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
5-VOLT SUPPLY CIRCUIT SHORTED TO SENSOR GROUND
5-VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1NOTE: If DTC P0641 or P0651 is present with this DTC, diagnose DTCs
P0641 and P0651 before diagnosing this DTC.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off, wait 30 seconds, then start and idle the engine.
With the DRB, read ECM DTCs.
Did this DTC reset?All
Ye s®Go To 2
No®Go To 5
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the ECM/PCM Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ECM/PCM Relay
connector.
Disconnect the Oil Pressure Sensor harness connector.
Turn the ignition on.
Measure the voltage between ground and the 5-volt Supply circuit at the Oil Pressure
Sensor harness connector.
Is the voltage above 1.0 volt?All
Ye s®Repair the 5-volt Supply circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 3
11 0
DRIVEABILITY - DIESEL

Symptom:
P0615-STARTER RELAY CIRCUIT SHORT CIRCUIT
When Monitored and Set Condition:
P0615-STARTER RELAY CIRCUIT SHORT CIRCUIT
When Monitored: With the ignition on.
Set Condition: The ECM detects a short to voltage on the Starter Relay Control circuit.
POSSIBLE CAUSES
INTERMITTENT CONDITION
SUBSTITUTE ECM/PCM RELAY
STARTER RELAY OUTPUT CIRCUIT SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, erase ECM DTCs.
Attempt to start the engine several times, 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 2
No®Go To 4
2 Turn the ignition off.
Install a substitute relay in place of the Starter Relay.
Attempt to start the engine several times, 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®Replace the Starter Relay.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Remove the Starter Relay from the IPM.
Turn the ignition on.
Measure the voltage of the Starter Relay Output circuit.
Is the voltage below 1.0 volt?All
Ye s®Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No®Repair the Starter Relay Output circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
124
DRIVEABILITY - DIESEL