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.
Fail-Safe Chart
If any of the following DTCs are set, the hybrid vehicle control ECU enters fail-safe mode to allow the vehicle to be driven temporarily or stops fuel injection.
| DTC | Component | Fail-safe Operation | Fail-safe Deactivation Condition |
|---|---|---|---|
| P0031 P0032 P101D |
Air fuel ratio sensor heater | Hybrid vehicle control ECU turns off air fuel ratio sensor heater | Power switch off |
| P0037 P0038 P102D |
Heated oxygen sensor heater | Hybrid vehicle control ECU turns off heated oxygen sensor heater | Power switch off |
| P0102 P0103 |
Mass air flow meter sub-assembly | Hybrid vehicle control ECU calculates ignition timing according to engine speed and throttle valve position | Pass condition detected |
| P0112 P0113 |
Intake air temperature sensor | Hybrid vehicle control ECU estimates intake air temperature to be 20°C (68°F) | Pass condition detected |
| P0115 P0117 P0118 |
Engine coolant temperature sensor | Hybrid vehicle control ECU estimates engine coolant temperature to be 80°C (176°F) | Pass condition detected |
| P0120 P0121 P0122 P0123 P0220 P0222 P0223 P0604 P0606 P0607 P060A P060E P0657 P2102 P2103 P2111 P2112 P2118 P2119 P2135 |
Electronic throttle control system | Hybrid vehicle control ECU cuts off throttle actuator current and throttle valve returns to the 6.5° throttle position by return spring. The hybrid vehicle control ECU stops the engine and the vehicle can be driven using solely the hybrid system.*1 |
Pass condition detected and then power switch turned off |
| P0327 P0328 |
Knock control sensor | Hybrid vehicle control ECU sets ignition timing to maximum retard | Power switch off |
| P0351 to P0354 | Ignition coil assembly (Igniter) |
Hybrid vehicle control ECU cuts fuel | Pass condition detected |
| U0028 U0037 |
Hybrid vehicle control ECU | Hybrid vehicle control ECU stops the engine and the vehicle can be driven using solely the hybrid system | Pass condition detected |
HINT:
*1: The vehicle can be driven slowly when the accelerator pedal is depressed firmly and slowly.
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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.