AUTO LIGHT SYSTEM OPERATION
id091800526700
Operation
Illumination condition
Lights off condition
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Illumination operation
1. When the light switch is in the AUTO position, the illumination level sensors in the auto light sensor (installed in windshield) detect the illumination level above and in front of the vehicle.
2. If the illumination level sensor detects approx. 2,000 lux or less, a TNS on control signal is sent to the body control module (BCM).
3. When the microcomputer in the BCM receives the control signal, current (1) flows and transistor A is turned on.
4. When transistor A turns on, the TNS relay turns on. At the same time the TNS illuminate.
5. When the microcomputer in the BCM receives the control signal, current (2) flows and transistor B is turned on.
6. When the transistor turns on, the headlight relay turns on. At the same time the headlights (LO) illuminate.
2-Beam Type
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4-Beam Type
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Lights off operation
1. When the light switch is in the AUTO position, the illumination level sensors in the auto light sensor (installed in the windshield) detect the illumination level.
2. If the upward and forward illumination level sensor detect approx. 4,000 lux or more for 1.0 s in front of and above the vehicle, the headlight and TNS off control signal is sent to the BCM.
3. The microcomputer in the BCM receives the control signal and turns off the current to transistor A, causing the headlight relay to turn off.
4. When the headlight relay turns off, the headlights (LO) turn off.
5. The microcomputer in the BCM receives the control signal and turns off the current to transistor B, causing the TNS relay to turn off.
6. When the TNS relay turns off, the TNS turn off.
Fail-safe function
FAIL-SAFE FUNCTION TABLE
Malfunction
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Fail-safe function
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Recovery condition
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Before operation
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After operation
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• Auto-light sensor malfunction
• Auto-light sensor communication error
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Headlights on
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Headlights remain on
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• Ignition switch is turned off
• Auto-light sensor malfunction is not detected
• Communication is restored
• Light switch is turned to a position other than AUTO
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TNS on
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TNS remain on
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OFF (lights off)
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Lights remain off
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