Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
Diagnose and repair any O2 Sensor or fuel system related DTCs before proceeding with this diagnostic procedure.
1. Start the engine and allow it to reach operating temperature.
  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.
2. Test drive the vehicle according to the monitoring conditions.
3. With a scan tool, read DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic Procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K734) O2 2/1 POSITIVE CURRENT CONTROL CIRCUITS FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Check for continuity between ground and the (K734) O2 2/1 Positive Current Control circuit at the O2 Sensor 2/1 harness connector.
  Is there continuity between ground and the (K734) O2 2/1 Positive Current Control circuit?
  
  Yes
  - Repair the (K734) O2 2/1 Positive Current Control circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE O2 SENSOR 2/1 OPERATION
1. Turn the ignition off.
2. Reconnect the PCM C2 harness connector.
3. Replace the O2 Sensor 2/1 and reconnect the harness connector.
4. Turn the ignition on.
5. With the scan tool, erase DTCs.
6. Start the engine and allow it to idle long enough for the O2 Sensor to enter closed loop operation.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 4
  No
  - Repair is complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
NOTE:
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
1. Using the appropriate SYSTEM WIRING DIAGRAM/SCHEMATIC as a guide, inspect the wiring and connectors between the O2 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 O2 Sensor and Powertrain Control Module harness connectors.
4. Perform any Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .