Fail-Safe Chart
WARNING: This page is about a different car, the 2007 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
- HID headlight system
The light control ECU operates in the fail-safe mode if an abnormal condition such as those listed below has been detected.
FAIL-SAFE CHARTItem Outline Detection of abnormal input voltage (High input voltage) If voltage that is input to the light control ECU is approximately 20 V or more, the ECU stops illuminating the headlights, and resumes when the voltage drops to 16 V or less. Detection of abnormal input voltage (Low input voltage) If voltage that is input to the light control ECU is 6 V or less, the ECU stops illuminating the low beam headlights, and resumes when the voltage is 10 V or more. Detection of abnormal output - Open in output side circuit
- Short between output terminals
- Short between output terminal and body ground
If an abnormal condition occurs in the voltage that is output by the light control ECU, the ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the light control switch from OFF to HEAD) Detection of bulb flashing If the bulb flashing repeats within approximately 5 seconds and continues for approximately 60 seconds, the light control ECU stops illuminating low beam headlights and will maintain this state until the power is reinstated (by turning the light control switch from OFF to HEAD) Detection of abnormal light voltage (Low light voltage) After approximately 80 seconds since input voltage is supplied, if the light voltage is below approximately 31 V for approximately 0.5 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the light control switch from OFF to HEAD) Detection of abnormal light voltage (High light voltage) If the light voltage is above approximately 69 V for approximately 0.5 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the light control switch from OFF to HEAD) - Automatic headlight beam level control system
If the AFS ECU detects a malfunction in the automatic headlight beam level control system or intelligent AFS, it will take the actions indicated in the table below.
MALFUNCTION CHARTTrouble Area Condition (Fail-Safe Control for Automatic Headlight Beam Level Control) AFS OFF Indicator Light Headlight Swivel Motor Malfunction Continues control until a position that is 0.65° less than the current position is reached. Flash Steering Angle Sensor Signal Malfunction Continues control. Flash Speed Sensor Signal Malfunction - Continues to control using the normal speed sensor signal if one signal fails.
- Judges that the vehicle speed is 0 km/h and continues to control if both speed sensor signals fail.
Flash Height Control Sensor Signal Malfunction - Stops the operation after returning to the initial position (Fail at higher than the initial position).
- Stops the operation at the current position (Fail at lower than the initial position).
Flash Headlight Leveling Motor Malfunction Normal Side Headlight Leveling Motor - Stops the operation after returning to the initial position (Fail at higher than the initial position).
- Stops at the current position (Fail at lower than the initial position).
Flash Abnormal Side Headlight Leveling Motor - Stops at the current position.
Communication Signal Malfunction Skid Control ECU: - Judges that the vehicle speed is 0 km/h (0 mph) and continues control.
Flash Steering Angle Sensor: - Normally controls the system.
- Intelligent AFS
If the AFS ECU detects a malfunction in the intelligent AFS or automatic headlight beam level control system, it will take the actions indicated in the table below.
MALFUNCTION CHARTTrouble Area Condition (Fail-Safe Control for Intelligent AFS Control) AFS OFF Indicator Light Headlight Swivel Motor Normal Side Headlight Swivel Motor: - Stops operating after returning to the initial position.
Flash Abnormal Side Headlight Swivel Motor: - Stops at the current position.
Steering Angle Sensor Signal Malfunction Stops operating after returning to the initial position. Flash Speed Sensor Signal Malfunction Stops operating after returning to the initial position. Flash Height Control Sensor Signal Malfunction Stops operating after returning to the initial position. Flash Headlight Leveling Motor Stops operating after returning to the initial position. Flash Communication Signal Malfunction Main Body ECU: - Stops operating after returning to the initial position.
Flash ECM: - Stops operating after returning to the initial position.
Skid Control ECU: - Stops operating after returning to the initial position.
Steering Angle Sensor: - Stops operating after returning to the initial position.
- Automatic light control system
If the main body ECU detects a malfunction in the automatic light control sensor, the main body ECU effects fail-safe control to prohibit the automatic light control. If the low beam headlights and taillights are on, the lights will remain on until the light control switch is turned off.