Body Control Module (BCM) Interaction
POWER CONVERTIBLE TOPTOP CONTROL
The body control module controls all the functions of the convertible top. The body control module supplies a multiplexed voltage of approximately 90% of ignition voltage to the power top switch. Through a series of resistors the power top switch switches the circuit to ground depending on the position of the switch. The BCM then supplies the ground path for the up or down relay as requested. The power top switch has a 4.7 K-ohm diagnostic resistor that allows the BCM to detect a possible open circuit.
WINDOW DROP RELAY ASSEMBLY
The convertible has a feature that allows the operator to lower all four windows and lower the top at the same time. This is accomplished by pressing the power top switch to the second detent. Through the multiplexed circuit of the power top switch the BCM will supply the ground for the window drop relay assembly.
The window drop relay assembly is comprised of four separate relays that are in series with the power window circuits. The relay assembly is located in the driver door.