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.
- Start the engine.
- Allow the engine to reach normal operating temperature.
- 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 .
- CHECK THE EXHAUST SYSTEM FOR LEAKS
- 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
- Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS
.
- CHECK THE (K243) O2 SENSOR 2/2 SIGNAL CIRCUIT FOR PROPER VOLTAGE
- Turn the ignition off
- Disconnect the O2 Sensor 2/2 harness connector.
- Turn the ignition on.
- Measure the voltage between ground and the (K243) O2 Sensor 2/2 Signal circuit in the O2 Sensor 2/2 harness connector.
Is the voltage between 4.1 and 5.0 volts?
Yes
- Go To 4
No
- Check the (K243) O2 Sensor 2/2 Signal circuit for a short to ground, open or short to voltage. If OK, Go To 6
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE (K904) O2 SENSOR 2/2 RETURN CIRCUIT FOR PROPER VOLTAGE
- Measure the voltage between ground and the (K904) O2 Sensor 2/2 Return circuit in the O2 Sensor 2/2 harness connector.
Is the voltage at 2.5 volts?
Yes
- Go To 5
No
- Check the (K904) O2 Sensor 2/2 Return circuit for a short to ground, open or short to voltage. If OK, Go To 6
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the voltage between ground and the (K904) O2 Sensor 2/2 Return circuit in the O2 Sensor 2/2 harness connector.
- CHECK THE OXYGEN SENSOR FOR PROPER OPERATION NOTE:
Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant.
- Using the appropriate SYSTEM WIRING DIAGRAM/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/2 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.
- 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 2/2 in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK RELATED HARNESS CONNECTIONS
- Disconnect all PCM harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- 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.
- Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- 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 .
- 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 .