If any of the following DTCs are set the ECM enters failsafe mode to allow the vehicle to be driven temporarily

DTCs

Components

Fail-Safe Operations

Fail-Safe Deactivation Conditions

P0031, P0032, P0051 and P0052

Air-Fuel Ratio (A/F) Sensor Heater

ECM turns off A/F sensor heater.

Ignition switch OFF

P0037, P0038, P0057 and P0058

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, P0328, P0332 and P0333

Knock Sensor

ECM sets ignition timing to maximum retard.

Ignition switch OFF

P0351 to P0356

Igniter

ECM cuts fuel.

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 of circuits malfunctions, ECM controls engine using other circuit.

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

Pass condition detected and then ignition switch turned OFF

NOTICE:

* 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.

P0031 Toyota Sienna
Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook


Post a comment