Home › Engine/Hybrid System › Engine Control › 3UR-FE ENGINE CONTROL: SFI SYSTEM
Last Modified: 11-27-2007 1.6 U
Service Category: Engine/Hybrid System Section: Engine Control
Model Year: 2008 Model: LX570 Doc ID: RM000000PDO051X
Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: FAIL-SAFE CHART (2008 LX570)

FAIL-SAFE CHART

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

DTC

Component

Fail-Safe Operation

Fail-Safe Deactivation Condition

P0031, P0032, P0051 and P0052

Air-Fuel Ratio (A/F) Sensor Heater

The ECM turns off the A/F sensor heater.

Engine switch off

P0037, P0038, P0057 and P0058

Heated Oxygen (HO2) Sensor Heater

The ECM turns off the HO2 sensor heater.

Engine switch off

P0102 and P0103

Mass Air Flow (MAF) Meter

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

Pass condition detected

P0110, P0112 and P0113

Intake Air Temperature (IAT) Sensor

The ECM estimates the IAT to be 20°C (68°F).

Pass condition detected

P0115, P0117 and P0118

Engine Coolant Temperature (ECT) Sensor

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

Pass condition detected

P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0604, P0606, P060A, P060B, P060D, P060E, P0657, P2102, P2103, P2111, P2112, P2118, P2119 and P2135

Electronic Throttle Control System (ETCS)

The ECM cuts off throttle actuator current and the throttle valve is returned to a 7° throttle position by the return spring.

The ECM then adjusts the engine output by controlling fuel injection (intermittent fuel cut) and ignition timing in accordance with the accelerator pedal opening angle to allow the vehicle to continue at minimal speed*1.

Pass condition detected and then engine switch turned off

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 and P0308*2
  • Fuel injector
  • Electronic Throttle Control System (ETCS)

When a misfire occurs, fuel cut is performed for catalyst overheat malfunction prevention.

  • With a normal load and normal engine speed (MIL is blinking):

    - Fuel cut is performed on the malfunctioning cylinder.

  • With a high load and high engine speed driving (MIL is blinking):

    - Throttle valve opening angle control is performed.

    - Fuel cut is performed on all cylinders or the malfunction cylinder.

Pass condition detected and then engine switch turned off

P0327, P0328, P032C, P032D, P0332, P0333, P033C and P033D

Knock Sensor

The ECM sets the ignition timing to maximum retard.

Engine switch off

P0351 to P0358

Ignition Coil

The ECM cuts fuel.

Pass condition detected

P0504

Stop Light Switch

The accelerator pedal angle is fixed.

Accelerator pedal angle is fixed

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

Accelerator Pedal Position (APP) Sensor

The APP sensor has 2 sensor circuits: Main and Sub.

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

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

Pass condition detected and then engine switch turned off

P2432, P2433, P2437 and P2438

Secondary Air Injection System

Throttle valve opening angle control is performed.

Pass condition detected

P2440 and P2442

Secondary Air Injection System

Throttle valve opening angle control is performed.

Pass condition detected

P2445 and P2447

Secondary Air Injection System

Throttle valve opening angle control is performed.

Pass condition detected

HINT:

  • *1: 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.
  • *2: Misfire related fail-safe operations occur when catalyst overheat malfunctions occur.