Diagnostic Test

CHECK FOR AN ACTIVE CONDITION
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 -64°C (-83°F) until the engine coolant temperature is equal, or close to the environmental ambient temperature.
3. Turn the ignition on.
4. With the scan tool, compare the ECT Sensor reading to the other temperature sensor values.
  Is the Engine Coolant Temperature (ECT) Sensor value within 20°C (36°F) of the other temperature sensor values?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  No
  - Go To 2
CHECK THE ECT SENSOR (K2) TEMP SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the ECT Sensor harness connector.
3. Disconnect the PCM C2 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 GPEC Diagnostic Adaptor to perform the diagnosis.
4. Connect the (special tool No. 10436, Adapter, GPEC Diagnostic) to the appropriate PCM connector.
  NOTE:
  The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.
5. Measure the resistance of the ECT Sensor (K2) Temp Signal circuit between the ECT Sensor harness connector and the GPEC Diagnostic Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the ECT Sensor (K2) Temp Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K900) Sensor Ground circuit between the ECT Sensor harness connector and the GPEC Diagnostic Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K900) Sensor ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE ABILITY OF THE PCM TO READ THE ECT SENSOR (K2) TEMP SENSOR SIGNAL
1. Turn the ignition off.
2. Connect the PCM harness connector(s).
3. Turn the ignition on.
4. With the scan tool, read DTCs.
  NOTE:
  The DTC - P0118-ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT HIGH should display as active or pending with the ECT Sensor harness connector disconnected.
5. Turn the ignition off.
6. Connect a fused jumper between the ECT Sensor (K2) Temp Signal circuit and the (K900) Sensor Ground circuit at the ECT Sensor harness connector.
7. Turn the ignition on.
8. With the scan tool, read DTCs.
  NOTE:
  The DTC - P0117-ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW should display as active or pending with the jumper in place.
  
  Does the scan tool display as described above?
  
  Yes
  - Replace the Engine Coolant Temperature (ECT) Sensor in accordance with the Service Information. Refer to SENSOR, COOLANT TEMPERATURE, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .