Diagnostic Test

CHECK FOR AN INTERMITTENT CONNECTION IN THE ENGINE WIRING HARNESS
NOTE:
Diagnose any active or pending Sensor Reference High or Sensor Reference Low DTCs before proceeding with this test procedure. If this DTC is present without an active or pending Sensor Reference High or Sensor Reference Low DTC, the most likely cause is an intermittent open or short circuit in the wiring harness between the engine and the PCM.
1. Turn the ignition off.
2. Disconnect the MAP Sensor harness connector.
3. Connect a voltmeter to the (F856) 5-Volt Supply circuit at the MAP Sensor harness connector.
  NOTE:
  Make sure that there is a good positive connection between the voltmeter lead and the MAP Sensor harness connector terminal since we are looking for an intermittent connection.
4. Turn the ignition on.
5. While monitoring the voltage reading on the voltmeter, wiggle test the entire engine wiring harness all the way to the PCM.
  NOTE:
  Look for any quick changes in the voltmeter reading. The voltmeter should read steady 5.0 volts +/-.01 or.02 volts with the Throttle Body Assembly harness connector unplugged.
  
  Did the voltmeter reading change from 5.0 volts at any time while wiggle testing the wiring?
  
  Yes
  - Repair the (F856) 5-Volt Supply circuit for an intermittent open or short circuit in the wiring harness. Make sure to check all of the in-line connectors for poor connections or spread terminals.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 2
CHECK FOR AN INTERMITTENT CONNECTION IN THE APP WIRING HARNESS
1. Turn the ignition off.
2. Disconnect the APP Sensor harness connector.
3. Connect a voltmeter to the (K854) 5-Volt Supply circuit at the APP Sensor harness connector.
4. Turn the ignition on.
5. While monitoring the voltage reading on the voltmeter, wiggle test the wiring harness between the APP Sensor and the PCM.
  Did the voltmeter reading change from 5.0 volts at any time while wiggle testing the wiring?
  
  Yes
  - Repair the (K854) 5-Volt Supply circuit for an intermittent open or short circuit in the wiring harness. Make sure to check all of the in-line connectors for poor connections or spread terminals.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE SECONDARY SENSORS
1. Turn the ignition off.
2. Reconnect the MAP Sensor harness connector.
3. Reconnect the APP Sensor harness connector.
4. Disconnect the PCM C2 harness connector and connect the (special tool #10436, Adapter, GPEC Diagnostic) in-line with the PCM C2 harness connector.
5. Connect a voltmeter to the (F856) 5-Volt Supply circuit at the GPEC Adaptor.
6. Turn the ignition on.
7. While monitoring the voltage reading on the voltmeter, lightly tap on each sensor listed in the possible causes table.
  Did the voltmeter reading change from 5.0 volts at any time while tapping on one of the sensors?
  
  Yes
  - Replace the sensor that caused the voltage to change.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
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 the Powertrain Control Module 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
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  - Test complete.