Diagnostic Test

1) DTC IS ACTIVE
Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes
1. Go to 2).
No
1. Refer to the *CHECKING FOR AN INTERMITTENT CONDITION Diagnostic Procedure.
2) (K2) ECT 1 SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 1: Measuring Voltage Of (K2) ECT 1 Signal Circuit In Engine Coolant Temperature Sensor 1 Harness Connector
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Engine Coolant Temperature Sensor 1 connector.

Disconnect the Powertrain Control Module (PCM) connector.

Turn the ignition on.

Measure the voltage of the (K2) ECT 1 Signal circuit in the Engine Coolant Temperature Sensor 1 harness connector.

Is there any voltage present?

Yes
1. Repair the (K2) ECT 1 Signal circuit for a short to voltage.
2. Perform PCM VERIFICATION TEST .
No
1. Go to 3).
3) (K2) ECT 1 SIGNAL OPEN OR HIGH RESISTANCE

Fig 2: Checking ECT Sensor 1 Signal Circuit For Open Or High Resistance
Courtesy of CHRYSLER LLC

Turn the ignition off.

Measure the resistance of the (K2) ECT 1 Signal circuit between the Engine Coolant Temperature Sensor 1 harness connector and the Powertrain Control Module (PCM) harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Go to 4).
No
1. Repair the (K2) ECT 1 Signal circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
4) (K900) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 3: Checking ECT Sensor Ground Circuit For Open Or High Resistance
Courtesy of CHRYSLER LLC

Measure the resistance of the (K900) Sensor Ground circuit between the Engine Coolant Temperature Sensor 1 harness connector and the Powertrain Control Module (PCM) harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Go to 5).
No
1. Repair the (K900) Sensor Ground circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
5) ENGINE COOLANT TEMPERATURE SENSOR 1

Fig 4: Connecting Jumper Wire Between ECT Sensor 1 Signal Circuit And Sensor Ground Circuit In ECT Sensor 1 Harness Connector
Courtesy of CHRYSLER LLC

Turn the ignition off.

Connect the Powertrain Control Module (PCM) connector.

Connect a jumper wire between the (K2) ECT 1 Signal circuit and the (K900) Sensor Ground in the Engine Coolant Temperature Sensor 1 harness connector.

Turn the ignition on.

With the scan tool, read the Engine Coolant Temperature Sensor 1 signal voltage.

Is the voltage below 1.0 volt with the jumper wire in place?

Yes
1. Replace the Engine Coolant Temperature Sensor 1 in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .
No
1. Go to 6).
6) POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Coolant Temperature Sensor 1 and the Powertrain Control Module (PCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals.

Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.

Look for the data to change or for the DTC to reset during the wiggle test.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes
1. Repair as necessary.
2. Perform PCM VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .