Symptom:
P2306-SENSOR SUPPLY 2 VOLTAGE IS TOO LOW
POSSIBLE CAUSES
BOOST PRESSURE SENSOR
FUEL PRESSURE SENSOR
VISUAL WIRING AND CONNECTOR INSPECTION
INTERMITTENT CONDITION
SENSOR SUPPLY VOLTAGE 2 SHORTED TO GROUND
BOOST PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
ENGINE CONTROL MODULE
FUEL PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
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.
Turn the ignition on.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 8
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.
Measure the resistance between ground and all of the Fuel Pressure Sensor and
Boost Pressure Sensor harness connector cavities.
Is the voltage below 1000 ohms for any of the measurements?All
Ye s!Repair the circuit(s) that measured below 1000 ohms for a short to
ground.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
200
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between the Sensor Ground circuit and the Fuel Pressure
Sensor Signal circuit at the Fuel Pressure Sensor harness connector.
Is the resistance above 1000 ohms?All
Ye s!Go To 5
No!Repair the Fuel Pressure Sensor Signal circuit for a short to the
Sensor Ground circuit.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the Boost Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between the Sensor Ground circuit and the Boost Pressure
Sensor Signal circuit at the Boost Pressure Sensor harness connector.
Is the resistance above 1000 ohms?All
Ye s!Go To 6
No!Repair the Boost Pressure Sensor Signal circuit for a short to the
Sensor Ground circuit.
Perform ROAD TEST VERIFICATION - VER-2.
6 Turn the ignition off.
Disconnect the Boost 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!Go To 7
No!Replace the Boost Pressure Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
7 Turn the ignition off.
Disconnect the Fuel 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 Fuel Pressure Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
201
DRIVEABILITY - DIESEL
P2306-SENSOR SUPPLY 2 VOLTAGE IS TOO LOW ÐContinued
Symptom:
P2332-SENSOR SUPPLY 3 VOLTAGE IS TOO LOW
POSSIBLE CAUSES
ENGINE OIL SENSOR
INTAKE AIR PRESSURE SENSOR
VISUAL WIRING AND CONNECTOR INSPECTION
INTERMITTENT CONDITION
SENSOR SUPPLY VOLTAGE 3 SHORTED TO GROUND
ENGINE CONTROL MODULE
ENGINE OIL SENSOR SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
INTAKE AIR PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
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.
Turn the ignition on.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 8
2 Turn the ignition off.
Visually inspect the wiring and connectors associated with the Intake Air Pressure
Sensor and Engine Oil Sensors 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 Intake Air Pressure Sensor and Engine Oil Sensor harness connec-
tors.
Disconnect the ECM harness connectors.
Measure the resistance between ground and all of the EOS and Intake Air Pressure
Sensor harness connector cavities.
Is the voltage below 1000 ohms for any of the measurements?All
Ye s!Repair the circuit(s) that measured below 1000 ohms for a short to
ground.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
203
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the Engine Oil Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between the Sensor Ground circuit and the Engine Oil Sensor
Signal circuit at the Engine Oil Sensor harness connector.
Is the resistance above 1000 ohms?All
Ye s!Go To 5
No!Repair the Engine Oil Sensor Signal circuit for a short to the
Sensor Ground circuit.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the Intake Air Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between the Sensor Ground circuit and the Intake Air
Pressure Sensor Signal circuit at the Intake Air Pressure Sensor harness connector.
Is the resistance above 1000 ohms?All
Ye s!Go To 6
No!Repair the Intake Air Pressure Sensor Signal circuit for a short to
the Sensor Ground circuit.
Perform ROAD TEST VERIFICATION - VER-2.
6 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!Go To 7
No!Replace the Intake Air Pressure Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
7 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!Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Replace the Engine Oil Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
204
DRIVEABILITY - DIESEL
P2332-SENSOR SUPPLY 3 VOLTAGE IS TOO LOW ÐContinued
TEST ACTION APPLICABILITY
3 Turn the ignition on.
With the DRBIIIt, read the CAB DTCs.
Are there any CAB DTCs?All
Ye s!Refer to symptom list for problems related to CAB.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
4 Turn the ignition off.
Disconnect the CAB Module harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of each CAN Bus circuit between the ECM harness connector
and the CAB harness connector.
Is the resistance below 10.0 ohms for each measurement?All
Ye s!Go To 5
No!Repair the open CAN Bus circuit(s) between the ECM and the
SKREEM.
Perform ROAD TEST VERIFICATION - VER-2.
5 With the DRBIIIt, perform the Wheel Speed Test of the ABS system.
Were any problems found?All
Ye s!Repair wheel speed signal problem as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 6
6 Check the Brake Switch for proper operation and adjustment.
Were any problems found?All
Ye s!Adjust or replace the Brake Switch as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Test Complete.
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.
210
DRIVEABILITY - DIESEL
P2333-S/C VEHICLE SPEED PLAUSIBILITY ÐContinued
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
TEST ACTION APPLICABILITY
7 Turn the ignition off.
Install a substitute EGR Solenoid in place of the vehicle's EGR Solenoid.
NOTE: Ensure the ECM and EGR Valve harness connectors are connected.
Turn the ignition on.
With the DRB, check for this DTC to set again.
Did this DTC set again?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 EGR Solenoid.
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.
220
DRIVEABILITY - DIESEL
P2511-EGR VALVE SIGNAL CIRCUIT SHORTED TO GROUND ÐContinued