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
AMBIENT AIR 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 value within 10°C (18°F) of the other two sensor values?
  
  Yes
  - Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 3
ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE
1. Turn the ignition off.
2. Disconnect the Engine Coolant Temperature Sensor harness connector.
3. Turn the ignition on.
4. With a scan tool, read the Engine Coolant Temperature Sensor voltage.
  NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 of a volt) with the connector disconnected.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Go to step 4
  No
  - Go to step 5
ENGINE COOLANT TEMPERATURE SENSOR
1. Turn the ignition off.
2. Connect a jumper wire between the (K2) ECT Signal circuit and the (K900) Sensor Ground circuit in the Engine Coolant Temperature Sensor harness connector.
3. Turn the ignition on.
4. With a scan tool, read the Engine Coolant Temperature Sensor voltage.
  NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus.1 of a volt) with the jumper wire in place.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Replace the Engine Coolant Temperature Sensor.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 5
(K2) ECT SIGNAL CIRCUIT HIGH RESISTANCE
1. Turn the ignition off.
2. Connect the Engine Coolant Temperature Sensor 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 the PCM Pinout Box 8815 along with the Adapter 8815-1 to perform the diagnosis.
3. Using a voltmeter, perform a voltage drop test by backprobing the (K2) ECT Signal circuit at the Engine Coolant Temperature Sensor harness connector and probing the appropriate terminal of the PCM Pinout Box 8815. Make sure the voltmeter leads are connected so that 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 hand near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.
4. Start the engine.
  Is the voltage below 0.5 of a volt?
  
  Yes
  - Go to step 6
  No
  - Repair the (K2) ECT Signal circuit for high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K900) SENSOR GROUND CIRCUIT HIGH RESISTANCE
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 PCM Pinout Box 8815 along with the Adapter 8815-1 to perform the diagnosis.
2. Using a voltmeter, perform a voltage drop test by backprobing the (K900) Sensor Ground circuit at the Engine Coolant Temperature Sensor harness connector and probing the appropriate terminal of the PCM Pinout Box 8815. Make sure the voltmeter leads are connected so that 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 hand near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.
3. Start the engine.
  Is the voltage below 0.5 of a volt?
  
  Yes
  - Go to step 7
  No
  - Repair the (K900) Sensor Ground circuit for high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Coolant Temperature 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.
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. Perform 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 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 .