Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Brake Signal: Description and Operation

BRAKE ON/OFF (BOO) SWITCH
Sends a battery voltage signal to PCM when depressing brake pedal.

Operation
PCM adjusts or controls the following:
1. Maintains idle speed with brake applied
2. A/C compressor ON/OFF
3. Disengages torque converter clutch

NOTE: If all stop lamp bulbs are open, a high voltage is present at PCM due to a pull-up resistor in PCM. This provides fail safe function in event circuit to BOO switch has failed.