Diagnostic Test

CHECK FOR CONTAMINANTS OR DAMAGE TO THE O2 SENSOR
1. Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.
  Are there contaminants that may have damaged the O2 Sensor present?
  
  Yes
  - Perform the appropriate repairs.
    After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 2
CHECK FOR AN ACTIVE DTC
1. Start the engine and allow the engine to reach normal operating temperature.
2. Test drive the vehicle according to the set conditions.
3. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 3
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE EXHAUST SYSTEM FOR LEAKS
1. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS .
  Were any exhaust leaks found?
  
  Yes
  - Repair or replace the leaking exhaust parts as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT VOLTAGE OUTPUT
1. Turn the ignition off.
2. Disconnect the O2 Sensor 1/2 harness connector.
3. Turn the ignition ON.
4. Measure the voltage on the (K141) O2 Sensor 1/2 Signal circuit in the O2 Sensor 1/2 harness connector.
  Is the voltage between 0.09 and 0.12 volts?
  
  Yes
  - Go To 5
  No
  - Check the O2 Sensor 1/2 Signal circuit for a short to ground, open or short to voltage. If OK, replace and program the PCM in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K904) O2 SENSOR RETURN CIRCUIT VOLTAGE VALUE
1. Measure the voltage on the (K904) O2 Sensor Return circuit at the O2 Sensor 1/2 harness connector.
  Is the voltage at 0.11 volts?
  
  Yes
  - Go To 6
  No
  - Check the (K904) O2 Sensor Return circuit for a short to ground, open or short to voltage. If OK, replace and program the PCM in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE OXYGEN SENSOR OPERATION
1. Using the appropriate SYSTEM WIRING DIAGRAMS/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/2 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.
4. Perform any Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the Oxygen Sensor 1/2 in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .