Diagnostic Test

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
NOTE:
While this fault could set due to a faulty O2 Sensor or wiring, it is more likely to set due a mechanical, fuel or air handling issue. If the vehicle exhibits any fuel system or driveability issues, or has any other fuel or air handling system DTCs (I.E. O2 Sensor circuit, MAP Sensor, Fuel Injector, Ignition Coil, etc.), diagnose and repair those concerns before proceeding with this test.
1. Refer to the recorded DTCs.
  Are there any fuel system, air handling system or O2 Sensor DTCs active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DIAGNOSTIC CODE INDEX .
  No
  - Go To 3
CHECK THE EXHAUST SYSTEM FOR RESTRICTIONS
1. Start the engine and check for good exhaust flow at the tailpipe.
2. Visually inspect the exhaust system for any damage that could cause a restriction.
  Were any problems found?
  
  Yes
  - Perform the appropriate repair in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE MAP SENSOR OPERATION
1. Perform the CHECKING THE MAP SENSOR OPERATION test procedure. Refer to CHECKING THE MAP SENSOR PERFORMANCE .
  Were any problems found?
  
  Yes
  - Repair as necessary in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
PURGE SOLENOID OPERATION
1. Turn the ignition off.
2. Disconnect the hoses at the Purge Solenoid.
3. Using a hand vacuum pump, apply 5.0 in. Hg. to the "ENGINE" side of the Purge Solenoid.
  NOTE:
  The solenoid should hold vacuum for a minimum of 15 seconds.
  
  Did the Purge Solenoid hold vacuum?
  
  Yes
  - Go To 6
    NOTE:
    Connect the vacuum hoses before continuing.
  No
  - Verify that there is good pin to terminal contact in the Evap Purge Solenoid and Powertrain Control Module connectors. Replace the Purge Solenoid if no problems were found with the connectors.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE FUEL DELIVERY SYSTEM
1. Perform the CHECKING THE FUEL DELIVERY SYSTEM test procedure. Refer to CHECKING THE FUEL DELIVERY SYSTEM (HARD START) .
  Were any problems found?
  
  Yes
  - Perform the appropriate repair in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
CHECK THE ENGINE MECHANICAL OPERATION
1. Check for any of the following conditions/mechanical problems:
  - AIR INDUCTION SYSTEM - must be free from restrictions.
  - ENGINE VALVE TIMING - must be within specifications.
  - ENGINE COMPRESSION - must be within specifications.
  - FUEL - must be free of contamination.
  - FUEL INJECTOR - if a Fuel Injector is suspected of leaking or abnormal spray pattern, remove the fuel rail with the injectors intact. Energize the fuel pump to maintain fuel pressure in the fuel rail. Check for any fuel leakage before the suspect injector is actuated. Actuate the suspect Fuel Injector(s) with the scan tool and inspect the fuel spray pattern for abnormalities. Compare with the other injectors.
  Are there any engine mechanical problems?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8
CHECK THE EGR VALVE OPERATION
1. Turn the ignition off.
2. Block EGR flow to the engine.
3. Turn the ignition on and monitor the short term adaptive reading.
4. Start the engine. Allow the engine to idle and monitor the short term adaptive for up to five minutes.
  Did the short term adaptive increase with the EGR flow blocked?
  
  Yes
  - Replace the EGR Valve in accordance with the Service Information. Refer to VALVE, EXHAUST GAS RECIRCULATION (EGR), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 9
CHECK THE UPSTREAM O2 SENSOR WIRING
NOTE:
While this fault could set due to a faulty O2 Sensor or wiring, it is more likely to set due to poor engine performance. If the vehicle exhibits any fuel system or driveability issues, or has any other fuel or air handling system DTCs (I.E. O2 Sensor circuit, MAP Sensor, Fuel Injector, Ignition Coil, etc.), diagnose and repair those concerns before proceeding with this test.
1. Disconnect the Upstream O2 Sensor harness connector.
2. 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.
3. Connect the (special tool #10436, Adapter, GPEC Diagnostic)
4. Check the Upstream O2 Sensor circuits;
  - for a short to ground in the wiring between the O2 Sensor harness connector and the PCM C2 harness connector.
  - for an open or high resistance in the wiring between the O2 Sensor harness connector and the PCM C2 harness connector.
  Were any problems found?
  
  Yes
  - Perform the appropriate repair.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 10
REPLACE THE OXYGEN SENSOR AND RETEST FOR DTC
1. Replace the Upstream O2 Sensor in accordance with the Service Information. Refer to UPSTREAM O2 SENSORS or DOWNSTREAM O2 SENSORS .
2. Connect the Bank 2 Upstream O2 Sensor and PCM harness connectors.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Using the Freeze Frame Data or When Monitored Conditions above, operate the vehicle within the conditions that set the DTC.
  Did the DTC return?
  
  Yes
  - Go To 11
  No
  - Replacing the Upstream O2 Sensor repaired the fault.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
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, 3.6L (GPEC 2A) .
  - 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 .