Symptom:
P2306-SENSOR SUPPLY 2 VOLTAGE IS TOO HIGH
POSSIBLE CAUSES
BOOST PRESSURE SENSOR
FUEL PRESSURE SENSOR
VISUAL WIRING AND CONNECTOR INSPECTION
INTERMITTENT CONDITION
SENSOR SUPPLY VOLTAGE 2 SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off for 10 seconds.
Start the engine.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 6
2 Turn the ignition off.
Visually inspect the wiring and connectors associated with the Boost Pressure Sensor
and Fuel Pressure Sensor for problems that may result in a short circuit.
Were any problems found?All
Ye s!Repair or replace wiring/connectors as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 3
3 Turn the ignition off.
Disconnect the Boost Pressure Sensor and Fuel Pressure Sensor harness connectors.
Disconnect the ECM harness connectors.
Remove the Engine Control Relay.
Connect a jumper wire between cavity 30 and cavity 87 of the Engine Control Relay
connector in Fuse Block No.1.
Turn the ignition on.
Measure the voltage at all circuits in the Fuel Pressure Sensor and Boost Pressure
Sensor harness connector cavities.
Is the voltage above 1.0 volt for any of the measurements?All
Ye s!Repair the circuit(s) that measured above 1.0 volt for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
198
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the Intake Air Pressure Sensor and Engine Oil Sensor harness connec-
tors.
Disconnect the ECM harness connectors.
Remove the Engine Control Relay.
Connect a jumper wire between cavity 30 and cavity 87 of the Engine Control Relay
connector in Fuse Block No.1.
Turn the ignition on.
Measure the voltage at all circuits in the Engine Oil Sensor and Intake Air Pressure
Sensor harness connector cavities.
Is the voltage above 1.0 volt for any of the measurements?All
Ye s!Repair the circuit(s) that measured above 1.0 volt for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
4 Turn the ignition off.
Disconnect the Engine Oil Sensor harness connector.
Turn the ignition on.
With the DRBIIIt, erase ECM DTCs.
Turn the ignition off for 10 seconds. Turn the ignition on.
With the DRBIIIt, read ECM DTCs.
Does the DRB display this DTC?All
Ye s!Go To 5
No!Replace the Engine Oil Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the Intake Air Pressure Sensor harness connector.
Turn the ignition on.
With the DRBIIIt, erase ECM DTCs.
Turn the ignition off for 10 seconds. Turn the ignition on.
With the DRBIIIt, read ECM DTCs.
Does the DRB display this DTC?All
Ye s!Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Replace the Intake Air Pressure Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
207
DRIVEABILITY - DIESEL
P2332-SENSOR SUPPLY 3 VOLTAGE IS TOO HIGH ÐContinued
Symptom:
P2351-ECM SUPPLY VOLTAGE TOO LOW
POSSIBLE CAUSES
ECM
ECM IGNITION CIRCUIT OPEN
STARTER OR LIFT PUMP RELAY CIRCUIT(S) SHORTED TO GROUND
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off for 10 seconds.
Test drive the vehicle.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 4
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the Starter Relay and disconnect the Fuel Lift Pump harness connector
Measure the resistance between ground and the Starter Relay control circuit.
Measure the resistance between ground and the Fuel Lift Pump Relay control circuit.
Did both circuits measure above 1000 ohms?All
Ye s!Go To 3
No!Repair the relay control circuit(s) that did not measure above
1000 ohms for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Using the Service Wiring Information determine which circuits in the ECM harness
connector provide Ignition Switch power to the ECM.
Turn the ignition on.
Using a 12-volt test light connected to ground, check each Ignition Switch Output
circuits in the ECM harness connectors.
Does the test light illuminate brightly for each circuit?All
Ye s!Replace the ECM in accordance with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Repair the Ignition Supply circuit as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
214
DRIVEABILITY - DIESEL
Symptom List:
P2511-EGR VALVE SIGNAL CIRCUIT SHORTED TO GROUND
P2527-EGR VALVE SIGNAL CIRCUIT OPEN CIRCUIT
P2527-EGR VALVE SIGNAL CIRCUIT SHORTED TO GROUND
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2511-EGR VALVE SIGNAL
CIRCUIT SHORTED TO GROUND.
POSSIBLE CAUSES
CHECKING THE ENGINE CONTROL RELAY SYSTEM
INTERMITTENT CONDITION
ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN
EGR VALVE CONTROL CIRCUIT SHORTED TO GROUND
EGR VALVE CONTROL CIRCUIT OPEN
EGR SOLENOID
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1NOTE: If DTC P1611, P2306 or P2332 is present with this DTC, diagnose
DTCs P1611, P2306 or P2332 before diagnosing this DTC.
NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
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 set again?All
Ye s!Go To 2
No!Go To 8
2NOTE: Check the ECM for other ECM DTC's related to circuits that are
open, shorted to ground or low voltage problems.
Does the DRB also display these type of DTC's?All
Ye s!Go To 3
No!Go To 4
218
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Connect a jumper wire between ground and the Engine Control Relay Signal circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C2 harness connector cavities 1, 3 and 5.
Does the test light illuminate brightly for each circuit?All
Ye s!Go To 4
No!Refer to symptom list and perform Checking the ECM Power and
Grounds.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the EGR Valve harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Engine Control Relay
Output circuit in the EGR Valve harness connector.
Does the test light illuminate brightly?All
Ye s!Go To 5
No!Repair the Engine Control Relay Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the EGR Valve harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between the EGR Valve Control circuit in the EGR Valve
harness connector and ground.
Is the resistance above 1000 ohms?All
Ye s!Go To 6
No!Repair the EGR Valve Control circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
6 Turn the ignition off.
Disconnect the EGR Valve harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the EGR Valve Control circuit.
Is the resistance below 10.0 ohms?All
Ye s!Go To 7
No!Repair the EGR Valve Control circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
219
DRIVEABILITY - DIESEL
P2511-EGR VALVE SIGNAL CIRCUIT SHORTED TO GROUND ÐContinued
Symptom List:
P2514-CRANKCASE VENT HEATER OPEN CIRCUIT
P2514-CRANKCASE VENT HEATER SHORTED TO GROUND
P2514-CRANKCASE VENT HEATER SHORTED TO VOLTAGE
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2514-CRANKCASE VENT
HEATER OPEN CIRCUIT.
POSSIBLE CAUSES
CHECKING ECM POWER AND GROUNDS
CHECKING THE ENGINE CONTROL RELAY SYSTEM
INTERMITTENT CONDITION
CRANKCASE VENT HEATER SHORTED TO VOLTAGE
CRANKCASE VENT HEATER CIRCUIT SHORTED TO GROUND
CRANKCASE HEATER VENT CIRCUIT(S) OPEN
CRANCASE VENT HEATER
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
NOTE: The engine should be cold for this test to be accurate.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Perform several engine run cycles, turning the ignition off for at least 10 seconds
between each engine run cycle.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 7
221
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Connect a jumper wire between ground and the Engine Control Relay Control circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C2 harness connector cavities 1, 3 and 5.
Choose the appropriate result.All
Test light is on for all circuits.
Go To 3
Test light is on for 1 or 2 circuits
Repair the Engine Control Relay Output circuit(s) that did not
illuminate brightly for an open.
Perform ROAD TEST VERIFICATION - VER-2.
Light off for all circuits.
Refer to symptom Checking the ECM Power and Grounds.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Disconnect the Crankcase Vent Heater harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the both circuits between the Crankcase Vent Heater
harness connector and the ECM harness connector.
Is the resistance below 10.0 ohms for each measurement?All
Ye s!Go To 4
No!Repair the Crankcase Vent Heater circuit(s) for an open.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the Crankcase Vent Heater harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between ground and both of the Crankcase Vent Heater
circuits.
Is the resistance above 1000 ohms for each circuit?All
Ye s!Go To 5
No!Repair the Crankcase Vent Heater circuit(s) for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the Crankcase Vent Heater harness connector.
Disconnect the ECM harness connectors.
Turn the ignition on.
Measure the voltage of the both Crankcase Vent Heater circuits.
Is the voltage below 1.0 volt for each circuit?All
Ye s!Go To 6
No!Repair the Crankcase Vent Heater circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
222
DRIVEABILITY - DIESEL
P2514-CRANKCASE VENT HEATER OPEN CIRCUIT ÐContinued
TEST ACTION APPLICABILITY
4NOTE: If DTC P1611 or P2306 is present with this DTC, diagnose DTCs P1611
and P2306 before diagnosing this DTC.
Turn the ignition off.
Disconnect the EGR Valve harness connector.
Disconnect the ECM harness connectors.
Remove the Engine Control Relay.
Connect a jumper wire between cavity 30 and cavity 87 of the Engine Control Relay
connector.
Turn the ignition on.
Measure the voltage of the EGR Valve Control circuit.
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!Repair the EGR Valve Control circuit for a short to voltage.
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.
226
DRIVEABILITY - DIESEL
P2527-EGR VALVE SIGNAL CIRCUIT SHORTED TO VOLTAGE ÐContinued