TEST ACTION APPLICABILITY
3NOTE: The engine temperature must be below 50ÉC (120ÉF) for this test.
NOTE: The thermostat must be operating correctly for this test to be valid.
With the DRBIIItin Sensors, read and note the engine coolant temperature.
Using a temperature probe, measure the engine block temperature near the ECT
Sensor.
Are the readings within 7ÉC (13ÉF) of each other?All
Ye s!Go To 4
No!Go To 5
4NOTE: The thermostat must be operating correctly for this test to be valid.
Start the engine and bring the engine to operating temperature (thermostat open).
Turn the engine off and wait 10 minutes to allow the engine temperature to stabilize.
Using a temperature probe, measure the engine block temperature near the ECT
Sensor.
With the DRBIIIt, select Engine, then Sensors and read the engine coolant
temperature.
Are the readings within 7ÉC (13ÉF) of each other?All
Ye s!Replace the Engine Oil Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 5
5 Disconnect the ECT harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the ECT Sensor Signal circuit between the ECM harness
connector and the ECT harness connector.
Measure the resistance of the Sensor Ground circuit between the ECM harness
connector and the ECT harness connector.
Is the resistance below 10.0 ohms for each measurement?All
Ye s!Replace the Engine Coolant Temperature Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
No!Repair the ECT Sensor circuit(s) that measured above 10.0 ohms
for high resistance.
Perform ROAD TEST VERIFICATION - VER-2.
43
DRIVEABILITY - DIESEL
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT PLAUSIBILITY
WITH ENGINE OIL SENSOR Ð
Continued
Symptom List:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLT-
AGE TOO HIGH
P2054-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLT-
AGE TOO HIGH
P2054-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLT-
AGE TOO LOW
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0115-ENGINE COOLANT TEMP
SENSOR CIRCUIT SIGNAL VOLTAGE TOO HIGH.
When Monitored and Set Condition:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLTAGE TOO
HIGH
When Monitored: With the ignition on.
Set Condition: The Engine Coolant Temperature Sensor Signal voltage is above 4.98 volts
for more than 3 seconds.
P2054-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLTAGE TOO
HIGH
When Monitored: With the ignition on.
Set Condition: The Engine Coolant Temperature Sensor Signal voltage is above 4.98 volts
for more than 3 seconds.
P2054-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLTAGE TOO
LOW
When Monitored: With the ignition on.
Set Condition:
POSSIBLE CAUSES
INTERMITTENT CONDITION
ECM ECT SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
ECT SENSOR GROUND CIRCUIT OPEN
ECT SENSOR
ECT SENSOR SIGNAL CIRCUIT OPEN
ENGINE CONTROL MODULE
44
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
TEST ACTION APPLICABILITY
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.
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.
46
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
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the ECT Sensor harness connector.
Measure the resistance between ground and the ECT Sensor Signal circuit.
Is the resistance above 1000 ohms?All
Ye s!Go To 4
No!Repair the ECT Sensor Signal circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the ECT Sensor harness connector.
Measure the resistance between the ECT Sensor Signal circuit and Sensor Ground
circuit.
Is the resistance above 1000 ohms?All
Ye s!Go To 5
No!Repair the ECT Sensor Signal and Ground circuits for a short
together.
Perform ROAD TEST VERIFICATION - VER-2.
5 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.
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.
48
DRIVEABILITY - DIESEL
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLTAGE
TOO LOW Ð
Continued
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
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the Fuel Temperature Sensor harness connector.
Connect a jumper wire between the Fuel Temperature Sensor harness connector
cavities.
Turn the ignition on.
With the DRB, read the Fuel Temperature Sensor voltage.
Is the voltage below 1.0 volt?All
Ye s!Replace the Fuel Temperature Sensor in accordance with the
Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
4 Turn the ignition off.
Disconnect the Fuel Temperature Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Fuel Temperature Sensor Ground circuit.
Is the resistance below 10.0 ohms?All
Ye s!Go To 5
No!Repair the Fuel Temperature Sensor Ground circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Fuel Temperature Sensor harness connector.
Measure the resistance of the Fuel Temperature Sensor Signal circuit.
Is the resistance below 10.0 ohms?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 Temperature Sensor Signal circuit for an open.
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.
50
DRIVEABILITY - DIESEL
P0180-FUEL TEMPERATURE SENSOR CIRCUIT - SIGNAL VOLTAGE
TOO HIGH Ð
Continued