Fail-Safe Chart
WARNING: This page is about a different car, the 2012 Lexus LS 460. However, it is still accessible from the selected car via links, so may be relevant.
- Headlight control ECU
The headlight control ECU operates in the fail-safe mode if an abnormal condition such as those listed below has been detected.
Item Outline Detection of abnormal input voltage (High input voltage) If voltage that is input to the headlight 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 headlight 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 headlight 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 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 headlight 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 headlight 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) - AFS ECU
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.
Trouble Area Leveling Fail-safe Control Swivel Fail-safe Control AFS OFF Indicator Light Headlight Swivel Motor Malfunction Continues to control with both headlight leveling motors lower than current position by 0.65° Stops malfunctioning swivel motor at current position Flash Steering Sensor Signal Malfunction Continues to control Returns both headlight swivel motors back to front Speed Sensor Signal Malfunction Continues to control After 5 seconds, returns both headlight swivel motors back to front Height Control Sensor Signal Malfunction - Stops operation after returning to initial position (Fail at higher than initial position)
- Stops operation at current position (Fail at lower than initial position)
Returns both headlight swivel motors back to front Headlight Leveling Motor Malfunction Normal side headlight leveling motor - Stops operation after returning to initial position (Fail at higher than initial position)
- Stops at current position (Fail at lower than initial position)
Returns both headlight swivel motors back to front Abnormal side headlight leveling motor - Stops at current position
Communication Signal Malfunction Skid control ECU: - Judges that vehicle speed is 0 km/h (0 mph) and continues control
Returns both headlight swivel motors back to front Steering sensor: - Continues to control
- AUTOMATIC HIGH BEAM SYSTEM
- The main body ECU (multiplex network body ECU) operates in fail-safe mode if an abnormal condition, such as those listed below, has been detected.
Item Abnormality Detection Condition Return Condition Warning Indicator Steering Sensor Signal Malfunction Steering sensor malfunction is detected. Steering sensor malfunction is not detected, and engine switch is turned on (IG) again. Flashes Steering sensor zero point memory invalid is detected. Steering sensor zero point memory valid is detected. Not illuminated Steering sensor data continuity invalid is detected. Steering sensor data continuity invalid flag is detected. Not illuminated Speed Sensor Signal Malfunction Abnormal speed sensor signal is detected. Normal speed sensor signal is detected. Flashes CAN Communication Signal Malfunction Normal CAN communication signal is not detected for more than 5 seconds consecutively. Normal CAN communication signal is detected. Flashes Automatic High Beam Sensor Communication stopped for 10 seconds consecutively. Normal communication signal is detected. Flashes
- The main body ECU (multiplex network body ECU) operates in fail-safe mode if an abnormal condition, such as those listed below, has been detected.