Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnostic Test
- CHECK FOR AN ACTIVE DTC
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- 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 .
- CHECK FOR OTHER DTCS
- Refer to the recorded DTCs.
Are there any other O2 Sensor or fuel system DTCs active or pending?
Yes
- Perform the applicable diagnostic procedure(s). Refer to PCM DIAGNOSTIC CODE INDEX .
No
- Go To 3
- Refer to the recorded DTCs.
- CHECK THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Turn the ignition off.
- Disconnect the Powertrain Control Module (PCM) C2 harness connector.
- Disconnect the O2 Sensor 1/1 harness connector.
- Check for continuity between ground and the (K41) O2 Sensor 1/1 Signal circuit at the O2 Sensor 1/1 harness connector.
Is there continuity between ground and the (K41) O2 Sensor 1/1 Signal circuit?
Yes
- Repair the (K41) O2 Sensor 1/1 Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 4
- REPLACE THE O2 SENSOR 1/1 AND RETEST FOR DTC
- Replace the O2 Sensor 1/1 and in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
- Connect the O2 Sensor 1/1 and PCM C2 harness connectors.
- Turn the ignition on.
- With the scan tool, erase DTCs.
- Using the recorded Freeze Frame Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Go To 5
No
- Replacing the O2 Sensor 1/1 repaired the fault.
- 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 AND INSTALLATION .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Repair the poor connections.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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