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.
Possible Causes
| Possible Causes |
|---|
| INTERMITTENT DTC |
| (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| (K902) O2 RETURN (UP) CIRCUIT SHORTED TO VOLTAGE |
| (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO THE (K199) O2 2/1 HEATER CONTROL CIRCUIT |
| (K43) O2 2/1 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE |
| (K902) O2 RETURN (UP) CIRCUIT OPEN OR HIGH RESISTANCE |
| 2/1 OXYGEN SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to *PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
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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