Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
This DTC sets to indicate a general O2 Sensor system circuit or component failure. The PCM runs secondary tests to pinpoint which circuit has the failure. It is important to diagnose any correlating DTCs relating to this fault first. If there are no other DTCs correlating present, the most likely cause is related to an intermittent circuit or component failure.
1. Turn the ignition on.
2. With the scan tool, record then erase DTCs.
3. Start the engine and road test until it reaches normal operating temperature.
4. With the scan tool, read the pending, active or stored DTCs.
  Did any active or pending O2 sensor DTCs return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CORRELATING DTCS
1. Refer to the DTCs recorded in step one.
  Were there any other correlating pending, active or stored open circuit DTCs?
  
  Yes
  - Perform the diagnostics for the correlating DTC before continuing with this test procedure.
  No
  - Go To 3
CHECK THE O2 SENSOR CIRCUITS FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Measure the resistance of the:
  - (K41) O2 Sensor 1/1 Signal circuit between the O2 Sensor 1/1 harness connector and the PCM Connector.
  - (K902) O2 Sensor 1/1 Return circuit between the O2 Sensor 1/1 harness connector and the PCM Connector.
  - (K89) O2 Sensor 1/1 Current Pump Control circuit between the O2 Sensor 1/1 harness connector and the PCM Connector.
  - (K103) O2 Sensor 1/1 Pump Cell Current Trim at the O2 Sensor 1/1 harness connector and the PCM Connector.
  Is the resistance below 3.0 Ohms? for each of the above circuits?
  
  Yes
  - Go To 4
  No
  - Repair the circuit that measured above 3.0 Ohms for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE O2 SENSOR CIRCUITS FOR A SHORT TO GROUND
1. Disconnect the PCM C1 harness connector.
2. Check for continuity between ground and the:
  - (K41) O2 Sensor 1/1 Signal circuit at the O2 Sensor 1/1 harness connector.
  - (K902) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
  - (K89) O2 Sensor 1/1 Current Pump Control circuit at the O2 Sensor 1/1 harness connector.
  - (K103) O2 Sensor 1/1 Pump Cell Current Trim at the O2 Sensor 1/1 harness connector.
  Is there continuity between any of the above circuits and ground?
  
  Yes
  - Repair the above circuit(s) that showed continuity to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE O2 SENSOR CIRCUITS FOR A SHORT TO VOLTAGE
1. Reconnect the PCM C1 harness connector.
2. Measure for voltage at the:
  - (K41) O2 Sensor 1/1 Signal circuit at the O2 Sensor 1/1 harness connector.
  - (K902) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
  - (K89) O2 Sensor 1/1 Current Pump Control circuit at the O2 Sensor 1/1 harness connector.
  - (K103) O2 Sensor 1/1 Pump Cell Current Trim at the O2 Sensor 1/1 harness connector.
  NOTE:
  With the O2 Sensor disconnected, the PCM will power down the O2 Sensor and there should be no voltage on the circuits.
  
  Do any of the circuits measure above 0.5 volts?
  
  Yes
  - Repair the circuit that measured above 0.5 volts for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
O2 SENSOR
1. Replace the O2 Sensor accordance with the Service Information and reconnect the harness connector. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
2. Turn the ignition on.
3. With the scan tool, erase DTCs.
4. Start the engine and allow it to idle long enough for the O2 Sensor to enter closed loop operation.
5. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 7
  No
  - Repair is complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. 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.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. 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 .