AUTOHOLD SWITCH
id042000003400
Purpose
• The AUTOHOLD switch switches between the enabling/disabling of the AUTOHOLD.
Functions
• The AUTOHOLD switch displays the AUTOHOLD condition by turning on/flashing the built-in indicator light (AUTOHOLD standby indicator light).
• When the AUTOHOLD switch is pressed while the AUTOHOLD standby indicator light is off, the AUTOHOLD is enabled and the AUTOHOLD standby indicator light turns on. When the AUTOHOLD switch is pressed while the AUTOHOLD standby indicator light is on, the AUTOHOLD is disabled and the AUTOHOLD standby indicator light turns off.
Construction
• The AUTOHOLD switch is located on the upper panel.
Wiring diagram
Operation
Electric parking brake operation
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• When the AUTOHOLD switch is pressed, the contact point in the AUTOHOLD switch closes. When a finger is released from the AUTOHOLD switch, the contact point in the AUTOHOLD switch opens automatically.
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1. When the AUTOHOLD switch is operated, a operation signal is sent (1) to the ESU.
2. The ESU sends (2) the AUTOHOLD switch operation signal to the electronically controlled brake unit based on the switch operation signal.
3. When the electronically controlled brake unit receives the AUTOHOLD switch operation signal from the ESU, it switches the AUTOHOLD to enable/disable (3).
AUTOHOLD standby indicator light
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• The AUTOHOLD standby indicator light turns on/flashes according to the transistor operation in the ESU.
• When the AUTOHOLD is enabled, the AUTOHOLD standby indicator light turns on. When the AUTOHOLD is disabled, the AUTOHOLD standby indicator light turns off.
• When any of the following conditions are met with the AUTOHOLD standby indicator light on, the AUTOHOLD standby indicator light flashes.
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― Hold control or pressure increase control starts
― Brake fluid pressure reduction starts
― Engine stalls
― Driver's seat belt is not fastened
― Driver's door is opened from closed condition
