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.
- Start the engine and test drive the vehicle.
- With the scan tool, read DTCs and record on the repair order.
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
- 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 (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT
- Turn the ignition off.
- Disconnect the O2 Sensor 1/1 harness connector.
- Turn the ignition on.
- Measure the voltage on the (K41) O2 Sensor 1/1 Signal circuit in the O2 Sensor 1/1 harness connector.
Is the voltage between 4.1 and 5.0 volts?
Yes
- Go To 4
No
- Check the (K41) O2 Sensor 1/1 Signal circuit for a short to ground, open, or short to voltage. If no problems are found, replace and program the Powertrain Control Module in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE (K902) O2 SENSOR 1/1 RETURN CIRCUIT
- Measure the voltage on the (K902) O2 Sensor 1/1 Return circuit in the O2 Sensor 1/1 harness connector.
Is the voltage at 2.5 volts?
Yes
- Go To 5
No
- Check the (K902) O2 Sensor 1/1 Return circuit for a short to ground, open, or short to voltage. If no problems are found, replace and program the Powertrain Control Module in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the voltage on the (K902) O2 Sensor 1/1 Return circuit in the O2 Sensor 1/1 harness connector.
- O2 SENSOR 1/1 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 1/1 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 1/1 O2 Sensor and Powertrain Control Module 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 1/1 in accordance with the Service Information. Refer to: SENSOR, OXYGEN, REMOVAL, 6.4L and SENSOR, OXYGEN, INSTALLATION, 6.4L .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Using the appropriate SYSTEM WIRING DIAGRAM/schematic as a guide, inspect the wiring and connectors between the 1/1 Oxygen Sensor and the Powertrain Control Module (PCM).