Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.

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.
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 and record on the repair order.
  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 O2 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 on 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 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 O2 RETURN DOWNSTREAM CIRCUIT
1. Measure the voltage on 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
  - Go To 6
O2 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 Oxygen Sensor in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. 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, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  - Test complete.