Lexus IS250 IS220d GSE20 ALE20 - LIGHTING
LIGHTING SYSTEM - FAIL-SAFE CHART
| FAIL-SAFE |
Light control ECU
The light control ECU executes the fail-safe actions listed below in accordance with the item that has been detected.
| Item | Outline |
| Detection of Abnormal Input Voltage | If voltage that is input to the headlight beam level control ECU deviates from the operating voltage range (9 to 16 V), the ECU stops illuminating the headlights, and resumes illuminating the headlights once the voltage reverts to the operating voltage range However, if input voltage decreases after the headlights have illuminated, the headlights will remain illuminated as long as possible |
| Detection of Abnormal Output (open or short circuit) or Flashing Bulb | If an abnormal condition (open or short circuit) occurs in voltage that is output by the headlight beam level control ECU, or if the bulb flashes, the ECU stops illuminating the headlights and will maintain this state until power is reinstated (by turning the headlight control switch off and then on again) |
| Detection of Bulb Open | If a bulb is not inserted in its socket, the ECU stops generating high voltage until the bulb is inserted correctly and power is reinstated (by turning the headlight control switch off and then on again, or turning the engine switch off and then on (IG) again) |
AFS ECU
- HINT:
- If a malfunction is detected, the headlight swivel ECU assembly (AFS ECU) performs fail-safe operation. Depending on the malfunction, the ECU flashes at 1 Hz intervals or illuminates the AFS OFF indicator in the combination meter assembly.
- Warning massages are also shown on the multi-information display.
| Item | Detection condition | Leveling motor control | Swivel motor control | Operation restore condition | Indicator |
| Swivel motor (motor) | Open Short Overheat | Continues with the right and left leveling motor positions lowered by 0.8° from the current position. | The normal swivel motor returns to the front position. The abnormal swivel motor stops at the current position. | IG ON cycled | Blinks |
| Gear malfunction | IG ON cycled Position change is detected | ||||
| Stop position error | IG ON cycled Normal stop position is detected | ||||
| Swivel motor (sensor) | Open Short | Continues | Returns to the front position | IG ON cycled Normal stop position is detected | Blinks |
| Steering angle sensor | Trouble information is received Communication error | Continues with the right and left leveling motors positions lowered by 0.8°from the current position. Continues after the swivel motor returns to the front position. | Stops at the current position and then returns to the front position. | IG ON cycled Normal value is detected | Blinks |
| Speed sensor | Open Short | Continues using the normal vehicle speed signal that is supplied by the skid control ECU if one sensor is malfunctioning. Continues determining that the vehicle is stationary if both sensors are malfunctioning. | If one sensor is malfunctioning, the swivel motor is controlled using the normal vehicle speed signal that is supplied by the skid control ECU, and the motor returns to the front position. If both sensors are malfunctioning, the motor returns to the front position. | IG ON cycled | Blinks |
| Height control sensor | Open Short Pitch angle error Power source trouble | If the leveling motor position is higher than the initial position, the leveling motor is returned to the initial position. If the leveling motor position is lower than its initial position, the leveling motor stays at the current position. | Returns to the front position. | IG ON cycled Normal value is detected | Blinks |
| Leveling motor | Open Short Overheat | The abnormal leveling motor stops at the current position. The normal leveling motor returns to its initial position if its current position is higher than than the initial position. The normal leveling motor will stop at the current position if this position is lower than the initial position. | Returns to the front position. | IG ON cycled | Blinks |
| BEAN communication | Interruption of headlight signal communication Interruption of headlight signal from the windshield wiper switch assembly Interruption of steering sensor zero-point signal Interruption of front and rear wheels speed signal communication | Continues | Returns to the front position. | Signal is no longer interrupted. | Blinks |
| Interruption of AFS OFF switch signal | Illuminates | ||||
Interruption of engine speed signal communication Interruption of vehicle speed signal communication | Continues | Blinks | |||
| AFS ECU | ECU internal malfunction | Continues | Continues | IG ON cycled | Goes off |
| Wheel speed data error | Abnormal front wheel speed signal is received from the skid control ECU | Continues | Returns to the front position. | Normal signal is received | Blinks |
LEXUS IS250, IS220d / GSE20 ALE20