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When Monitored:
With ignition on and battery voltage greater than 10.4 volts.
Set Condition:
The circuit voltage to the ECM is above a calibrated threshold for a certainperiod of time.
Possible Causes
FAILED SENSOR
INTERMITTENT CONDITION
(K21) SENSOR SIGNAL CIRCUIT OPEN
(K916) RETURN CIRCUIT OPEN
SHORT IN HARNESS
ECM
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.FAILED SENSOR
Turn the ignition off.
Disconnect the IAT sensor harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance of the IAT sensor.
Is the resistance between 300 and 90k ohms?
Ye s>>
Go To 2
No>>
Replace the Intake Air Temperature Sensor/map sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
2.INTERMITTENT CONDITION
Reconnect the IAT harness connector.
Turn the ignition on.
With the scan tool, erase DTCs.
With the scan tool, read DTCs.
Is P0113 still set?
Ye s>>
Go To 3
No>>
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
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3.HIGH RESISTANCE OF SENSOR CONNECTOR
Turn the ignition off.
Disconnect the ECM harness connector(s).
Measure the resistance between the temperature sensor (K21) signal
and (K916) return circuit at the ECM harness connector with the sensor
connected
Is the resistance between 300 and 90k ohms?
Ye s>>
Go To 6
No>>
Go To 4
4.(K21) SIGNAL CIRCUIT OPEN
Measure the resistance of the sensor (K21) signal circuit between the
sensor harness connector and the ECM harness connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 5
No>>
Repair the open Sensor (K21) signal circuit or the harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
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5.(K916) RETURN CIRCUIT OPEN
Measure the resistance of the sensor (K916) Return circuit between the
sensor harness connector and the ECM harness connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 6
No>>
Repair the open (K916) return circuit or the harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
6.SHORT IN HARNESS
Check for a short circuit from (K21) signal circuit to all other circuits at
the ECM harness connector.
Istheresistancemorethan100kohms?
Ye s>>
Go To 7
No>>
Repair the short in the wiring harness or replace the har-
ness.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
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7.ECM
Reconnect the ECM harness connectors.
Turn the ignition on.
With the scan tool, erase DTCs.
While monitoring with scan tool, use a jumper wire and connect the
sensor (K21) signal circuit to the sensor (K916) return circuit at the sen-
sor harness connector.
Did the DTC P0112 set?
Ye s>>
Refer to the INTERMITTENT CONDITION Symptom (Diag-
nostic Procedure). (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING)
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Replace the ECM.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
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P0116-ENGINE COOLANT TEMPERATURE (ECT) SENSOR RATIONALITY
For a complete wiring diagramRefer to Section 8W.
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When Monitored:
While the engine is running.
Set Condition:
The ECM does not read a change in value from the sensor over time.
Possible Causes
LOW COOLANT LEVEL
COOLANT TEMPERATURE SENSOR
THERMOSTAT
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.LOW COOLANT LEVEL
With the engine cold, verify the level of coolant in the radiator.
Is the radiator full of coolant?
Ye s>>
Go To 2
No>>
Fill the radiator with coolant- refer to the owners manual for assistance.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
2.COOLANT TEMPERATURE SENSOR
Remove the temperature sensor and reconnect the wiring to the sensor.
Turn the ignition on.
Monitor scan tool, while heating the sensor with an external heat source (DO NOT USE OPEN FLAME).
Does the reading from the sensor increase at least 5 degrees F. on the scan tool?
Ye s>>
Go To 3
No>>
Replace the coolant temp sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
3.THERMOSTAT
NOTE: refer to the no trouble code test*Thermostat Testto ensure the thermostat is operating properly.
Is the thermostat operating properly?
Ye s>>
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Replace the Thermostat.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
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P0117-ENGINE COOLANT TEMPERATURE (ECT) SENSOR VOLTAGE TOO LOW
For a complete wiring diagramRefer to Section 8W.
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When Monitored:
With ignition on and battery voltage greater than 10.4 volts.
Set Condition:
The circuit voltage to the ECM falls below a calibrated threshold for a certain period of time.
Possible Causes
COOLANT TEMPERATURE SENSOR
INTERMITTENT CONDITION
(K2) SENSOR SIGNAL CIRCUIT SHORTED TO GROUND OR (K914) RETURN CIRCUIT
WIRING HARNESS SHORTED
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.COOLANT TEMPERATURE SENSOR
Turn the ignition off.
Disconnect the Coolant Temp sensor harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance of the Temp sensor.
Is the resistance between 300 and 90k ohms?
Ye s>>
Go To 2
No>>
Replace the Coolant Temperature sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
2.INTERMITTENT CONDITION
Reconnect the coolant temp sensor connected.
Turn the ignition on.
With the scan tool, erase DTCs.
With the scan tool, read DTCs.
Did the DTC reset?
Ye s>>
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
No>>
Go To 3