
Symptom List:
P0110-INTAKE AIR TEMP SENSOR SIGNAL VOLTAGE TOO HIGH
P2063-INTAKE AIR TEMP SENSOR CIRCUIT SIGNAL VOLTAGE
TOO HIGH
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0110-INTAKE AIR TEMP
SENSOR SIGNAL VOLTAGE TOO HIGH.
When Monitored and Set Condition:
P0110-INTAKE AIR TEMP SENSOR SIGNAL VOLTAGE TOO HIGH
When Monitored: With the ignition on.
Set Condition: The Intake Air Temperature Sensor Signal voltage is above 4.83 volts.
P2063-INTAKE AIR TEMP SENSOR CIRCUIT SIGNAL VOLTAGE TOO HIGH
When Monitored: With the ignition on.
Set Condition: The Intake Air Temperature Sensor Signal voltage is above 4.83 volts.
POSSIBLE CAUSES
CHECK FOR ACTIVE DTC
INTERMITTENT CONDITION
INTAKE AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
INTAKE AIR TEMP SENSOR GROUND CIRCUIT OPEN
INTAKE AIR TEMP SENSOR SIGNAL CIRCUIT OPEN
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.
Turn the ignition on.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 5
34
DRIVEABILITY - DIESEL 

Symptom List:
P0110-INTAKE AIR TEMP SENSOR SIGNAL VOLTAGE TOO LOW
P2063-INTAKE AIR TEMP SENSOR CIRCUIT SIGNAL VOLTAGE
TOO LOW
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0110-INTAKE AIR TEMP
SENSOR SIGNAL VOLTAGE TOO LOW.
When Monitored and Set Condition:
P0110-INTAKE AIR TEMP SENSOR SIGNAL VOLTAGE TOO LOW
When Monitored: With the ignition on.
Set Condition: The Intake Air Temperature Sensor Signal voltage is below 0.073 volt for
more than 60 seconds.
P2063-INTAKE AIR TEMP SENSOR CIRCUIT SIGNAL VOLTAGE TOO LOW
When Monitored: With the ignition on.
Set Condition: The Intake Air Temperature Sensor Signal voltage is below 0.073 volt for
more than 60 seconds.
POSSIBLE CAUSES
INTERMITTENT CONDITION
IAT SENSOR
INTAKE AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
INTAKE AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO SENSOR GROUND
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.
Monitor the DRB for ECM DTCs for at least 2 minutes.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 6
37
DRIVEABILITY - DIESEL 

Symptom:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT PLAUSIBILITY
WITH ENGINE OIL SENSOR
When Monitored and Set Condition:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT PLAUSIBILITY WITH EN-
GINE OIL SENSOR
When Monitored: With the engine running.
Set Condition: The ECT Sensor signal indicates a different engine temperature than the
EOS Sensor.
POSSIBLE CAUSES
CURRENT DTC
ECT SENSOR
ECT SENSOR - COLD
ECT SENSOR - HOT
ENGINE OIL SENSOR SENSOR
HGH RESISTANCE IN ECT SENSOR CIRCUITS
ENGINE COLD TOO LONG
TEST ACTION APPLICABILITY
1 Verify that the coolant level is correct.
Start the engine.
NOTE: The thermostat must be operating correctly for this test to be valid.
With the DRBIIIt, erase ECM DTCs.
With the DRBIIIt, set the engine RPM to 1500 and allow the engine to warm up for
10-15 minutes.
With the DRBIIIt, monitor the Engine Coolant Temperature value during the warm
up cycle. Make sure the transition of temperature change is smooth.
Did the engine temperature reach a minimum of 80É C (176É F)?All
Ye s!Go To 2
No!Refer to the Service Information for cooling system performance
diagnosis. The most probable cause is a Thermostat problem.
Also, refer to any related TSBs.
Perform ROAD TEST VERIFICATION - VER-2.
2 Turn the ignition on.
With the DRBIIIt, read the ECM DTCs.
Did this DTC return after performing the previous test?All
Ye s!Go To 3
No!Check for possible connecor or wiring problems at the ECT sensor
that may cause an intermittent problem. Repair as necessary.
Test Complete.
Perform ROAD TEST VERIFICATION - VER-2.
42
DRIVEABILITY - DIESEL 

TEST ACTION APPLICABILITY
1NOTE: If multiple DTCs are present, the most likely cause is a 5-Volt Supply
or Sensor Ground circuit shorted to voltage or ground. Refer to the Service
Information Wiring section for circuits that would affect multiple DTCs.
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, monitor the Engine Coolant Temperature (ECT) Sensor voltage.
Is the ECT Sensor voltage above 4.90 volts?All
Ye s!Go To 2
No!Go To 7
2 Turn the ignition off.
Disconnect the ECT Sensor harness connector.
Turn the ignition on.
Measure the voltage on the ECT Sensor Signal circuit.
Is the voltage above 5.5 volts?All
Ye s!Repair the ECT Sensor Signal circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 3
3 Turn the ignition off.
Disconnect the ECT Sensor harness connector.
Connect a jumper wire between the ECT Sensor harness connector cavities.
Turn the ignition on.
With the DRB, read the ECT Sensor voltage.
Is the voltage below 1.0 volt?All
Ye s!Replace the ECT Sensor in accordance with the Service Informa-
tion.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
4 Turn the ignition off.
Disconnect the ECT Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the ECT Sensor Ground circuit.
Is the resistance below 10.0 ohms?All
Ye s!Go To 5
No!Repair the ECT Sensor Ground circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the ECT Sensor harness connector.
Measure the resistance of the ECT Sensor Signal circuit.
Is the resistance below 10.0 ohms?All
Ye s!Go To 6
No!Repair the ECT Sensor Signal circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
45
DRIVEABILITY - DIESEL
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLTAGE
TOO HIGH Ð
Continued 

Symptom:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLT-
AGE TOO LOW
When Monitored and Set Condition:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLTAGE TOO
LOW
When Monitored: With the ignition on.
Set Condition: The Engine Coolant Temperature Sensor Signal voltage is below 0.1 volt
for more than 3 seconds.
POSSIBLE CAUSES
INTERMITTENT CONDITION
ECT SENSOR
ECT SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
ECT SENSOR SIGNAL AND GROUND CIRCUITS SHORTED TOGETHER
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, monitor the Engine Coolant Temperature (ECT) Sensor voltage.
Is the ECT Sensor voltage below 0.1 volt?All
Ye s!Go To 2
No!Go To 6
2 Turn the ignition off.
Disconnect the ECT Sensor harness connector.
Turn the ignition on.
With the DRB, read the ECT Sensor voltage.
Is the voltage above 4.0 volts?All
Ye s!Replace the ECT Sensor in accordance with the Service Informa-
tion.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 3
47
DRIVEABILITY - DIESEL 

Symptom:
P0180-FUEL TEMPERATURE SENSOR CIRCUIT - SIGNAL VOLT-
AGE TOO HIGH
When Monitored and Set Condition:
P0180-FUEL TEMPERATURE SENSOR CIRCUIT - SIGNAL VOLTAGE TOO HIGH
When Monitored: With the ignition on.
Set Condition: The fuel temperature sensor signal voltage is above 4.7 volts.
POSSIBLE CAUSES
INTERMITTENT CONDITION
FUEL TEMPERATURE SENSOR GROUND CIRCUIT OPEN
FUEL TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
FUEL TEMPERATURE SENSOR
FUEL TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1NOTE: If multiple DTCs are present, the most likely cause is a 5-Volt Supply
or Sensor Ground circuit shorted to voltage or ground. Refer to the Service
Information Wiring section for circuits that would affect multiple DTCs.
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, monitor the Fuel Temperature Sensor voltage.
Is the Fuel Temperature Sensor voltage above 4.80 volts?All
Ye s!Go To 2
No!Go To 6
2 Turn the ignition off.
Disconnect the Fuel Temperature Sensor harness connector.
Turn the ignition on.
Measure the voltage on the Fuel Temperature Sensor Signal circuit.
Is the voltage above 5.5 volts?All
Ye s!Repair the Fuel Temperature Sensor Signal circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 3
49
DRIVEABILITY - DIESEL 

Symptom List:
P0180-FUEL TEMPERATURE SENSOR CIRCUIT - SIGNAL VOLT-
AGE TOO LOW
P2625-FUEL TEMPERATURE SENSOR PLAUSIBILITY
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0180-FUEL TEMPERATURE
SENSOR CIRCUIT - SIGNAL VOLTAGE TOO LOW.
When Monitored and Set Condition:
P0180-FUEL TEMPERATURE SENSOR CIRCUIT - SIGNAL VOLTAGE TOO LOW
When Monitored: With the ignition on.
Set Condition: The fuel temperature sensor signal voltage is below 0.8 volt.
P2625-FUEL TEMPERATURE SENSOR PLAUSIBILITY
When Monitored: With the ignition on.
Set Condition: The Mass Air Flow Sensor Signal voltage is above 4.8 volts.
POSSIBLE CAUSES
INTERMITTENT CONDITION
FUEL TEMPERATURE SENSOR
FUEL TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
FUEL TEMPERATURE SENSOR SIGNAL AND GROUND CIRCUITS SHORTED TOGETHER
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, monitor the Fuel Temperature Sensor voltage.
Is the Fuel Temperature Sensor voltage below 0.10 volt?All
Ye s!Go To 2
No!Go To 5
51
DRIVEABILITY - DIESEL 

TEST ACTION APPLICABILITY
1WARNING: THE FUEL INJECTION PUMP SUPPLIES HIGH-PRESSURE
FUEL TO EACH INDIVIDUAL INJECTOR THROUGH HIGH-PRESSURE
FUEL LINES. FUEL UNDER HIGH PRESSURE CAN PENETRATE SKIN
AND CAUSE PERSONAL INJURY. WEAR SAFETY GOGGLES AND ADE-
QUATE PROTECTIVE CLOTHING.
NOTE: 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.
Cycle the ignition key on and off several times, leaving the key on for at least 10
seconds at a time.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 10
2 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Turn the ignition on.
Measure the voltage of the Fuel Pressure Sensor Signal circuit.
Select the appropriate voltage reading.All
Voltage is above 5.4 volts.
Go To 3
Voltage is between 4.7 and 5.4 volts.
Go To 4
Voltage is below 4.7 volts.
Go To 9
3 Turn the ignition off.
Disconnect the Fuel Pressure Sensor 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 Fuel Pressure Sensor Signal 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 Fuel Pressure Sensor Signal circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
54
DRIVEABILITY - DIESEL
P0190-FUEL PRESS SENSOR CIRCUIT MALF SIGNAL VOLTAGE TOO
HIGH Ð
Continued