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TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the IAT 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 on the IAT Sensor Signal circuit.
Is the voltage below 1.0 volt?All
Ye s!Go To 3
No!Repair the Intake Air Temperature Sensor Signal circuit for a
short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
NOTE: Remove the jumper wire.
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the IAT Sensor harness connector.
Measure the resistance of the Intake Air Temperature Sensor Signal circuit.
Is the resistance below 10.0 ohms?All
Ye s!Go To 4
No!Repair the Intake Air Temperature Sensor Signal circuit for an
open.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the IAT Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Sensor Ground circuit between the ECM harness
connector and the IAT Sensor harness connector.
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 Intake Air Temperature Sensor Ground circuit for an
open.
Perform ROAD TEST VERIFICATION - VER-2.
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TEST ACTION APPLICABILITY
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.
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P0110-INTAKE AIR TEMP SENSOR SIGNAL VOLTAGE TOO HIGH Ð
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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
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TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the IAT Sensor harness connector.
Turn the ignition on.
Monitor the DRB for ECM DTCs for at least 2 minutes.
Does the DRB display P0110 INTAKE AIR TEMP SIGNAL VOLTAGE TOO HIGH?All
Ye s!Replace the Intake Air Temperature Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 3
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the IAT Sensor harness connector.
Measure the resistance between ground and the Intake Air Temperature Sensor
Signal circuit.
Is the resistance above 1000 ohms?All
Ye s!Go To 4
No!Repair the Intake Air Temperature 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 IAT Sensor harness connector.
Measure the resistance between the Intake Air Temperature Sensor Signal circuit
and the Sensor Ground circuit.
Is the resistance above 1000 ohms?All
Ye s!Go To 5
No!Repair the Intake Air Temperature Sensor Signal circuit for a
short to the Sensor Ground circuit.
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.
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P0110-INTAKE AIR TEMP SENSOR SIGNAL VOLTAGE TOO LOW Ð
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TEST ACTION APPLICABILITY
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.
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P0110-INTAKE AIR TEMP SENSOR SIGNAL VOLTAGE TOO LOW Ð
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Symptom List:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT PLAUSIBILITY
P2012-ENGINE COOLANT TEMP SENSOR CIRCUIT PLAUSIBILITY
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 PLAUSIBILITY.
POSSIBLE CAUSES
ECT SENSOR
ECT SENSOR - COLD
ECT SENSOR - HOT
HGH RESISTANCE IN ECT SENSOR CIRCUITS
ENGINE COLD TOO LONG
TEST ACTION APPLICABILITY
1Note: The best way to diagnose this DTC is to allow the vehicle to remain
outside overnight in order to have a completely cold soaked engine.
Note: Extremely cold outside ambient temperatures may cause this DTC to
set.
Verify that the coolant level is correct.
Start the engine.
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.
2NOTE: 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 3
No!Go To 4
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TEST ACTION APPLICABILITY
3NOTE: 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!Test Complete.
No!Go To 4
4 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.
41
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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.
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DRIVEABILITY - DIESEL