L200 L4-2.2L VIN F (2002)
When DRL operation is not desired, the BCM does not provide ground for the DRL relay. When not energized (as when high beam headlamps are
desired) the DRL relay operates the right and left high beam headlamps as a parallel circuit (full battery voltage across each high beam headlamp).
For DRL operation, the parking brake must be fully released, the ignition switch must be in the RUN position and headlamp switch must be in the Off
position. Under normal operating conditions, the feedback voltage to the BCM measured at
Decklid/Liftgate Release
The trunk/Liftgate release is controlled by the body control module (BCM) circuit 382 providing battery voltage to the release solenoid. The BCM limits
the amount of time the solenoid can be activated to 9 seconds to prevent damage to the solenoid. Reactivation may not be allowed for as much as 30
seconds.
Release of the decklid/liftgate can be initiated by either the transmitter or the decklid/liftgate release switch. Activating the decklid/liftgate release switch
provides battery voltage to circuit 56. Because remote keyless entry is an internal function of the BCM, no additional external wiring is necessary for
transmitter input to the BCM. Decklid/liftgate release is not allowed by the BCM when vehicle speed is detected. The BCM receives vehicle speed serial
data from the engine controller. Trunk release in sedan vehicles has a valet switch to limit trunk access.
The BCM also monitors the state of the decklid/liftgate. When circuit 744 is grounded by the ajar switch, the BCM will alert the driver the
decklid/liftgate is ajar by turning On the ajar telltale.
Delayed Locking
The delayed locking feature will activate when a valid lock command is received from a transmitter while any door or trunk (hatch) remains open. The
BCM will delay locking the vehicle until all doors and deck lid (hatch) are closed. The lock command will execute with in 500 mS. after all doors and/or
decklid transition to closed. If during the delayed state a transmitter unlock command, door unlock switch input or the ignition switch changes state to
other than off the delayed locking command will cancel.
When the delayed locking feature is active in the delayed state the Body Control Module (BCM) will activate a chime at the rate of 50 chime per
minute for a duration of 3 chime cycles. If the condition or state changes the chime will continue until completion of the chime schedule.
This feature is available on all Saturn L-Series vehicles with Remote Keyless Entry (RKE).
Device Power
Battery voltage is supplied to the BCM by circuit 2540. This input is internally monitored by the BCM for proper operating voltage. The proper
operating voltage range is from 9 to 16 volts.
Display Dimming
Display dimming is controlled by the BCM based on input received from the dimming potentiometer. The dimming potentiometer is connected between
circuit 1359 and circuit 1381. The BCM monitors these inputs and provides a Pulse Width Modulated (PWM) output at circuit 8 to operate the display
lamps.
Dome/Rear Reading Lamps
Dome and rear reading lamp operation is through the Body Control Module (BCM) providing ground to circuit 156. When manually operated by their
respective local switches, the dome and rear reading lamps are grounded through circuit 450 and the right body ground splice pack.
Door Locking/Unlocking
Door locking/unlocking, by Remote Keyless Entry (RKE) or driver/all door lock switches, is control led through the BCM.
When a driver door unlock has been requested, the BCM switches circuit 1391 to battery voltage. This energizes the driver door unlock relay which
supplies power to the driver door lock motor. Grounding is achieved through the closed contacts of the all-door lock relay. Grounding is also achieved
through the windings of the all-door lock motors and the all-door unlock relay.
When an all-door unlock has been requested, the BCM switches circuit 194 to battery voltage. This energizes the all-door unlock relay which supplies
power to the all-door lock motors. Grounding is achieved through the closed contacts of the door lock relay. Grounding is also achieved through the
winding of the driver door lock motor and the driver door unlock relay.
When an all-door lock has been requested, the BCM switches circuit 195 to battery voltage. This energizes the all-door lock relay which supplies power
to all-door lock motors. Grounding is achieved through the closed contacts of the driver door unlock relay and all-door unlock relay.
Lock/Unlock power application is limited by the BCM to 7 seconds to protect lock motors.
ECU Malfunction
The BCM performs an Electrically Erasable Programmable Read-only Memory (EEPROM) checksum as a part of its internal diagnostics as the BCM is
operating. When the EEPROM checksum does not equal a predetermined value, DTC B1000 - ECU Malfunction sets. The checksum is the contents of
