Diagnostic Test

DTC IS ACTIVE
NOTE: Diagnose any CAN - C Communication DTCs before continuing.
1. Turn the ignition off.
2. If possible, allow the vehicle to sit with the ignition off for more than 480 minutes in an environment where the temperature is consistent and above - 7° C (19.4° F).
3. Test drive the vehicle. The vehicle must exceed 48 km/h (30 mph) during the test drive. Do not cycle the ignition off when the test drive is completed.
4. With a scan tool, select View DTCs.
  Is the status Active or Pending for this DTC?
  
  Yes
  - Go to step 3
  No
  - Go to step 2
ENGINE COOLANT TEMPERATURE
1. Turn the ignition off.
2. Allow the vehicle to sit with the ignition off in an environment where the temperature is consistent and above - 7° C (19.4° F) until the engine coolant temperature is equal to ambient temperature.
3. Turn the ignition on.
4. With a scan tool, compare the AAT, ECT, and IAT sensor values.
  Is the Engine Coolant Temperature Sensor 1 value within 10° C (18° F) of the other two sensor values?
  
  Yes
  - Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
  No
  - Go to step 3
(K2) ECT 1 SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 1: Measuring Voltage Of ECT 1 Signal Circuit In Engine Coolant Temperature Sensor 1 Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Engine Coolant Temperature Sensor 1 connector.
3. Disconnect the Powertrain Control Module (PCM) connector.
4. Turn the ignition on.
5. 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
  - Repair the (K2) ECT 1 Signal circuit for a short to voltage.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 4
(K2) ECT 1 SIGNAL CIRCUIT SHORTED TO GROUND

Fig 2: Measuring Resistance Between Ground And ECT 1 Signal Circuit In Engine Coolant Temperature Sensor 1 Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Measure the resistance between ground and the (K2) ECT 1 Signal circuit in the Engine Coolant Temperature Sensor 1 harness connector.
  Is the resistance above 100 ohms?
  
  Yes
  - Go to step 5
  No
  - Repair the (K2) ECT 1 Signal circuit for a short to ground.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K2) ECT 1 SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT

Fig 3: Measuring Resistance Between ECT 1 Signal Circuit And Sensor Ground Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (K2) ECT 1 Signal circuit and the (K900) Sensor Ground circuit in the Engine Coolant Temperature Sensor 1 harness connector.
  Is the resistance above 100 ohms?
  
  Yes
  - Go to step 6
  No
  - Repair the (K2) ECT 1 Signal circuit for a short to the (K900) Sensor Ground circuit.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K2) ECT 1 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 4: Measuring Resistance Of ECT 1 Signal Circuit
Courtesy of CHRYSLER LLC
1. 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
  - Go to step 7
  No
  - Repair the (K2) ECT 1 Signal circuit for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K900) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 5: Checking ECT Sensor Ground Circuit For Open Or High Resistance
Courtesy of CHRYSLER LLC
1. 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
  - Go to step 8
  No
  - Repair the (K900) Sensor Ground for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
ENGINE COOLANT TEMPERATURE SENSOR 1

Fig 6: Engine Coolant Temperature Sensor 1 Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Connect the Powertrain Control Module (PCM) connector.
3. Connect a jumper wire between the (K900) Sensor Ground circuit and the (K2) ECT 1 Signal circuit in the Engine Coolant Temperature Sensor 1 harness connector.
4. Turn the ignition on.
5. 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
  - Replace the Engine Coolant Temperature Sensor 1 in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 9
POWERTRAIN CONTROL MODULE (PCM)
1. 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).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Refer to any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .