Q45 V8-4.5L (VK45DE) (2002)
Door Lamp: Description and Operation
System Description
POWER SUPPLY AND GROUND
Power is supplied at all times
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to BCM terminal 105
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through 10 A fuse [No. 3, located in the fuse block (J/B) No. 1], and
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to all step lamps terminal 1
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through 10 A fuse [No.8, located in the fuse block (J/B) No. 1].
Ground is supplied to terminal 15 of driver door control unit through body grounds M24 and M114.
Ground is supplied to terminal 7 of passenger door control unit through body grounds M24 and M114.
Ground is also supplied to terminal 7 of rear LH door control unit and rear RH door control unit through body grounds B17 and B57 or B217 and B256.
OPERATING PROCEDURE
BCM is connected to driver door control unit as DATA LINE A-3. Then driver door control unit is connected to each door control unit. When any door
switch is in OPEN position, ground is supplied
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to BCM terminal 33, 37, 142, or 143
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through driver side, passenger side, rear LH or RH door switch.
Then BCM sends a signal to the driver door control unit (LCU 01) to turn on step lamp. With ground supplied, step lamp turns on.