Failsafe Chart

If any of the following DTCs are set, the ECM enters fail-safe mode to allow the vehicle to be driven temporarily.



Fail-Safe Operations

Fail-Safe Deactivation Conditions

P0031 and P0032

Air-Fuel Ratio (A/F) Sensor Heater

ECM turns off A/F sensor heater.

Ignition switch OFF

P0037 and P0038

Heated Oxygen (HO2) Sensor Heater

ECM turns off HO2 sensor heater.

Ignition switch OFF

P0100, P0102 and P0103

Mass Air Flow (MAF) Meter

ECM calculates ignition timing according to engine speed and throttle valve position.

Pass condition detected

P0110, P0112 and P0113

Intake Air Temperature (IAT) Sensor

ECM estimates IAT to be 20°C (68° F).

Pass condition detected

P0115, P0117 and P0118

Engine Coolant Temperature (ECT) Sensor

ECM estimates ECT to be 80°C (176° F).

Pass condition detected

P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0604, P0606, P0607, P0657, P2102, P2103, P2111, P2112, P2118, P2119 and P2135

Electronic Throttle Control System (ETCS)

ECM cuts off throttle actuator current and throttle valve returned to 6° throttle position by return spring.

ECM then adjusts engine output by controlling fuel injection (intermittent fuel-cut) and ignition timing in accordance with accelerator pedal opening angle to allow vehicle to continue at minimal speed*.

Pass condition detected and then ignition switch turned OFF

P0327 and P0328

Knock Sensor

ECM sets ignition timing to maximum retard.

Ignition switch OFF

P0351 to P0354


ECM cuts fuel.

Pass condition detected

P1550, P1551, P1552 and P1602


Alternator command is fixed.

Pass condition detected

P2120, P2121, P2122, P2123, P2125, P2127, P2128 and P2138

Accelerator Pedal Position (APP) Sensor

APP sensor has 2 sensor circuits: Main and Sub.

If either circuit malfunctions, ECM controls engine using other circuit.

If both circuits malfunction, ECM regards accelerator pedal as being released. As result, throttle valve closed and engine idles.

Pass condition detected and then ignition switch turned OFF


*: The vehicle can be driven slowly when the accelerator pedal is depressed firmly and slowly. If the accelerator pedal is depressed quickly, the vehicle may speed up and slow down erratically.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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  • cara
    How to fix rav4 p0351?
    8 years ago

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