Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
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.

NOTE:
Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.
1. Start the engine.
2. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
3. With the scan tool, read DTCs.
  NOTE:
  It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.
  
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to: INTERMITTENT CONDITION .
CHECKING 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
  - Perform the appropriate repairs.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to: POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT
1. Turn the ignition off
2. Disconnect the O2 Sensor 1/2 harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (K141) O2 Sensor 1/2 Signal circuit in the O2 Sensor 1/2 harness connector.
  Is the voltage between 4.1 and 5.0 volts?
  
  Yes
  - Go To 4
  No
  - Check the (K141) O2 Sensor 1/2 Signal circuit for a short to ground, open or short to voltage. If no problems are found, replace and program the 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 .
CHECK THE (K904) O2 SENSOR 1/2 RETURN CIRCUIT
1. Measure the voltage between ground and the (K904) O2 Sensor 1/2 Return circuit in the O2 Sensor 1/2 harness connector.
  Is the voltage at 2.5 volts?
  
  Yes
  - Go To 5
  No
  - Check the (K904) O2 Sensor 1/2 Return circuit for a short to ground, open or short to voltage. If no problems are found, replace and program the 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 .
OXYGEN SENSOR
NOTE:
Check for signs of contaminants that may have damaged the O2 Sensor 1/2, such as contaminated fuel, unapproved silicone, oil and coolant.
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the O2 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 AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to: POWERTRAIN VERIFICATION TEST .