Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
Check for contaminants that may have damaged the Oxygen Sensor: contaminated fuel, unapproved silicone, oil and coolant.

NOTE:
After the repairs have been made, verify proper Oxygen Sensor operation. If all the Oxygen Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining Oxygen Sensors.
1. Start the engine.
2. Allow the engine to reach normal 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.
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
  - Repair or replace the leaking exhaust parts as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE OXYGEN (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 O2 Sensor 1/2 Signal circuit in the O2 Sensor harness connector.
  Is the voltage between 0.09 and 0.12 volt?
  
  Yes
  - Go To 4
  No
  - Check the O2 1/2 Signal circuit for a short to ground, open or short to voltage. If OK, replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE OXYGEN RETURN DOWNSTREAM CIRCUIT
1. Measure the voltage between ground and the O2 Sensor Return Downstream circuit in the O2 Sensor 1/2 harness connector.
  Is the voltage at 2.5 volts?
  
  Yes
  - Go To 5
  No
  - Check the O2 Return Downstream circuit for a short to ground, open or short to voltage. If OK, replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, 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, 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 1/2 Oxygen Sensor and the Powertrain Control Module (PCM).
  - Look for any chafed, pierced, pinched or partially broken wires.
  - Look for broken, bent, pushed out or corroded terminals.
  - Verify that there is good pin to terminal contact in the 1/2 O2 Sensor and Powertrain Control Module harness connectors.
  - 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 O2 Sensor in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .