Page 617 of 2305

Symptom:
P2244-INSTRUMENT CLUSTER MESSAGE PLAUSIBILITY
POSSIBLE CAUSES
ENGINE CONTROL MODULE
INSTRUMENT CLUSTER DTCS
VERIFY INSTRUMENT CLUSTER COMMUNICATION
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIItattempt to communicate with the Instrument Cluster.
NOTE: If there are other DTCs set with this DTC, refer to the Symptom List
and repair other stored ECM DTCs before diagnosing this DTC.
Is the Instrument Cluster communicating with the DRB?All
Ye s!Go To 2
No!Refer to the appropriate symptom in the Body Diagnostic Infor-
mation.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition on.
With the DRBIIIt, read the Instrument Cluster DTCs.
Are there any Instrument Cluster DTCs?All
Ye s!Refer to symptom list for problems related to Instrument Cluster.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 3
3NOTE: 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 DRBIIIt, erase the ECM DTCs.
Turn the ignition off then turn the ignition on and wait 60 seconds.
With the DRBIIIt, read the 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 BODY VERIFICATION TEST - VER 1.
No!Go To 4
194
DRIVEABILITY - DIESEL
Page 618 of 2305

TEST ACTION APPLICABILITY
4WARNING: 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 BODY VERIFICATION TEST - VER 1.
No!Test Complete.
195
DRIVEABILITY - DIESEL
P2244-INSTRUMENT CLUSTER MESSAGE PLAUSIBILITY ÐContinued
Page 619 of 2305
Symptom List:
P2259-TORQUE REDUCTION MESSAGE FROM HVAC- PARITY ER-
ROR
P2259-TORQUE REDUCTION MESSAGE FROM HVAC- SWITCH
SIGNAL ERROR
P2259-TORQUE REDUCTION MESSAGE FROM HVAC- SWITCH
SIGNAL PLAUSIBILITY
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2259-TORQUE REDUCTION
MESSAGE FROM HVAC- PARITY ERROR.
POSSIBLE CAUSES
AUTOMATIC TEMP CONTROL DTC
TEST ACTION APPLICABILITY
1NOTE: This DTC indicates the presents of a problem or DTC in the ATC
Module.
View repair statement.All
Ye s!Refer to symptom list for problems related to Automatic Temper-
ature Control.
Perform ROAD TEST VERIFICATION - VER-2.
196
DRIVEABILITY - DIESEL
Page 620 of 2305
Symptom:
P229-INSTRUMENT CLUSTER MESSAGE - AMBIENT TEMPERA-
TURE SIGNAL PLAUSIBILITY
POSSIBLE CAUSES
INSTRUMENT CLUSTER DTC
TEST ACTION APPLICABILITY
1NOTE: This DTC indicates the presents of a problem with the Ambient Temp
Sensor input to the Instrument Cluster.
View repair statement.All
Ye s!Refer to symptom list for problems related to Instrument Cluster.
Perform ROAD TEST VERIFICATION - VER-2.
197
DRIVEABILITY - DIESEL
Page 621 of 2305

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
Page 622 of 2305

TEST ACTION APPLICABILITY
4 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!Go To 5
No!Replace the Fuel Pressure Sensor in accordance with the Service
Information.
Perform ROAD TEST VERIFICATION - VER-2.
5 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!Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Replace the Boost Pressure Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
6WARNING: 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.
199
DRIVEABILITY - DIESEL
P2306-SENSOR SUPPLY 2 VOLTAGE IS TOO HIGH ÐContinued
Page 623 of 2305

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
Page 624 of 2305

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