engine coolant DODGE RAM SRT-10 2006 Service User Guide

P0116-ENGINE COOLANT TEMPERATURE (ECT) SENSOR RATIONALITY
For a complete wiring diagramRefer to Section 8W.

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)

P0117-ENGINE COOLANT TEMPERATURE (ECT) SENSOR VOLTAGE TOO LOW
For a complete wiring diagramRefer to Section 8W.

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

P0118-ENGINE COOLANT TEMPERATURE (ECT) SENSOR VOLTAGE TOO HIGH
For a complete wiring diagramRefer to Section 8W.

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
COOLANT TEMPERATURE SENSOR
INTERMITTENT CONDITION
(K2) SIGNAL CIRCUIT OPEN
(K914) SENSOR RETURN CIRCUIT OPEN
(K2) SIGNAL CIRCUIT SHORTED
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.COOLANT TEMPERATURE SENSOR
Disconnect the coolant temperature sensor harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance of the coolant temperature 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 disconnected coolant temp sensor harness connector.
With the scan tool, erase DTCs.
With the scan tool, read DTCs.
Did the DTC return?
Ye s>>
Go To 3
No>>
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)

3.HIGH RESISTANCE IN CIRCUIT
Turn the ignition off.
Disconnect the ECM harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance between the (K2) temperature sensor signal
and (K914) return circuit at the ECM harness connector with the coolant
temp sensor harness connected.
Is the resistance between 300 and 90k ohms?
Ye s>>
Go To 6
No>>
Go To 4
4.(K2) SIGNAL CIRCUIT OPEN
Disconnect the coolant temperature sensor harness connector.
Measure the resistance of the (K2) coolant temperature sensor signal
circuit between the coolant temperature sensor connector and the ECM
connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 5
No>>
Repair or replace the open (K2) signal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

5.(K914) SENSOR RETURN CIRCUIT OPEN
Measure the resistance of the (K914) coolant temperature sensor return
circuit between the coolant temperature sensor connector and the ECM
connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 6
No>>
Repair or replace the open (K914) sensor return circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
6.(K2) SIGNAL CIRCUIT SHORTED
Measure the resistance of (K2) signal circuit to all other circuits at the
ECM harness connector.
Istheresistancemorethan100kohms?
Ye s>>
Go To 7
No>>
Repair or replace the (K2) coolant temperature sensor sig-
nal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

P0128-THERMOSTAT RATIONALITY
For a complete wiring diagramRefer to Section 8W.
When Monitored:
While the engine is running.
Set Condition:
The coolant temperature does not rise by a calibrated amount over a calibratedamountoftime.
Possible Causes
COOLING FAN
COOLANT TEMPERATURE SENSOR
THERMOSTAT
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.COOLING FAN
NOTE: refer to the no trouble code test*Fan Operation Testto ensure the fan is operating properly.
Is the cooling fan operating properly?
Ye s>>
Go To 2
No>>
Repair the cooling fan.
Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
2.COOLANT TEMPERATURE SENSOR
Operate the engine for 10 minutes while monitoring the coolant temperaturewiththescantool.
Did the coolant temperature change over time while the engine was running?
Ye s>>
Go To 3
No>>
Replace the coolant temperature sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 2 (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>>
Te s t C o m p l e t e .
No>>
Replace the thermostat.
Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

For a complete wiring diagramRefer to Section 8W.
When Monitored:
While the engine is running. .
Set Condition:
The engine coolant temperature is above a calibrated value for a calibratedamountoftime.
Possible Causes
ECT SENSOR
OTHER DTC’S
MECHANICAL FAILURE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.OTHER DTC’S
With the scan tool, read DTCs.
Are other Cooling system DTC’s present?
Ye s>>
Trouble shoot the other DTC’s first.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Go To 2
2.ECT SENSOR
Allow the engine to reach normal operating temperature.
Use a temperature probe and measure the engine temperature near the ECT Sensor.
With the scan tool, read the Engine Temperature.
Compare the temperature probe reading with the scan tool reading.
Are the readings within 10° of each other?
Ye s>>
Repair the cause of mechanical failure.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
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)