Fail-Safe Function

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

The Headlight Leveling Control ECU performs the fail-safe when detecting following troubles.

At this it lights the warning light ("HEADLIGHT LEVELING") on the combination meter (multi-information display

FAIL-SAFE FUNCTION

Trouble Area	System
1. Headlight leveling actuator	Open circuit Short circuit
2. Vehicle speed sensor	One vehicle speed signal is 0km/h and the other is 10km/h (8 MPH) or more.
3. Generator	Open circuit Short circuit
4. Height control sensor	Signal lever error
5. Pitch angle calculation error	Signal lever error

Recovery condition (The warning light goes off.)

In case of 1, 2 and 3: ignition switch OFF
In case of 4 and 5: ignition switch OFF or signal lever error cancellation