Diagnostic Test

ACTIVE DTC
1. 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 may result in possible serious or fatal injury.
  
  NOTE:
  Diagnose and repair any system voltage DTCs before continuing with this test.
2. With the scan tool, select View DTCs.
  Is the DTC Active at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
(K2) ECT SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 1: Checking ECT Signal Circuit For Short To Voltage
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the ECT Sensor harness connector.
3. Disconnect the PCM C2 harness connector.
4. Ignition on, engine not running.
5. Measure the voltage on the (K2) ECT Signal circuit in the ECT Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (K2) ECT Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
(K2) ECT SIGNAL CIRCUIT OPEN
1. Turn the ignition off.
  CAUTION:
  Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
2. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
3. Measure the resistance of the (K2) ECT Signal circuit from the ECT Sensor harness connector to the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the open in the (K2) ECT Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
(K900) SENSOR GROUND CIRCUIT OPEN
1. Measure the resistance of the (K900) Sensor ground circuit from the ECT Sensor harness connector to the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the open or excessive resistance in the (K900) Sensor ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
ECT SENSOR

Fig 2: Checking ECT Sensor Signal Circuit
Courtesy of CHRYSLER GROUP, LLC
1. Reconnect the PCM C2 harness connector.
2. Connect a jumper wire between the (K2) ECT Signal circuit and the (K900) Sensor ground circuit in the ECT harness connector.
3. Turn the ignition on.
4. With the scan tool, read ECT voltage.
  NOTE:
  The sensor voltage should be approximately 0.0 Volts (plus or minus 0.1 Volt) with the jumper wire in place.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors. If OK, replace the Engine Coolant Temperature Sensor. Refer to SENSOR, COOLANT TEMPERATURE, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
    NOTE:
    Remove the jumper wire before continuing.
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the ECT Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .