Diagnostic Test

ACTIVE DTC
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 the scan tool, select View DTCs.
  Is the DTC active or Pending at this time?
  
  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 greater than -7°C (19.4°F), until the engine coolant temperature is equal to the ambient temperature.
3. Turn the ignition on.
4. With the scan tool, compare the AAT, ECT, and IAT sensor values.
  Is the ECT sensor value within 10°C (18°F) of the other two sensor values?
  
  Yes
  - Refer to the INTERMITTENT CONDITION Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 3
ECT SENSOR VOLTAGE
1. Turn the ignition off.
2. Disconnect the ECT sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read the ECT sensor voltage.
  NOTE: The sensor voltage should be approximately 5.0 Volts (+/- 0.1 Volts) with the electrical connector disconnected.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Go to step 4
  No
  - Go to step 5
ECT SENSOR

Fig 1: ECT Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. With the scan tool, read the ECT sensor voltage.
2. Connect a jumper wire between the (K2) ECT signal circuit and the (K900) sensor ground circuit in the ECT sensor harness connector.
  NOTE: The sensor voltage should be approximately 0.0 Volts (+/- 0.1 Volts) 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 PCM connectors. If OK, replace the ECT sensor.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 5
    NOTE: Remove the jumper wire before continuing.
EXCESSIVE RESISTANCE IN THE (K2) ECT SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the C2 PCM harness connector.
  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 PCM Pinout Box 8815 and PCM Pinout Box Adapter 8815-1 to perform diagnosis.
3. Using a voltmeter perform a voltage drop test. Backprobe the (K2) ECT signal circuit at the ECT sensor harness connector and probe the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so a positive polarity is displayed on the voltmeter.
  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.
4. Start the engine and allow it to reach normal operating temperature.
5. Monitor the voltmeter.
  Is the voltage below 0.5 of a Volt?
  
  Yes
  - Go to step 6
  No
  - Repair the open in the (K2) ECT signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
EXCESSIVE RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
1. Turn the ignition off.
2. Move the voltmeter leads to backprobe the (K900) sensor ground circuit at the ECT sensor harness connector and to probe the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so a positive polarity is indicated on the voltmeter.
  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.
3. Start the engine and allow it to reach normal operating temperature.
4. Monitor the voltmeter.
  Is the voltage below 0.5 Volts?
  
  Yes
  - Go to step 7
  No
  - Repair the open in the (K900) sensor ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K2) ECT SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 2: Measuring Voltage On ECT Signal Circuit In ECT Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the special tool #8815 from the C2 PCM harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the (K2) ECT signal circuit in the ECT sensor harness connector.
  Is the there any voltage present?
  
  Yes
  - Repair the short to voltage in the (K2) ECT signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 8
(K2) ECT SIGNAL CIRCUIT SHORTED GROUND

Fig 3: Measuring Resistance Between Ground And ECT Signal Circuit In ECT Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Measure the resistance between ground and the (K2) ECT signal circuit in the ECT sensor harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the short to ground in the (K2) ECT signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 9
(K2) ECT SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

Fig 4: Measuring Resistance Between Sensor Ground Circuit And ECT Signal Circuit In ECT Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the C2 PCM harness connector.
3. Measure the resistance between the (K900) sensor ground circuit and the (K2) ECT signal circuit in the ECT sensor harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Repair the short to between the (K900) sensor ground circuit and the (K2) ECT signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
  No
  - Go to step 10
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and electrical 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 PCM connectors.
4. Refer to any Technical Service Bulletins (TSBs) that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the PCM in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .