Circuit/System Description

WARNING: This page is about a different car, the 2010 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Depending on the vehicle build date and BCM software level, the method to place the vehicle in the run mode will be different. Early vehicles that have not had the BCM replaced or reprogrammed will require two presses of the igniting mode switch to enter run mode. Late vehicles and vehicles that have had the BCM replaced or reprogrammed require the ignition mode switch be pressed and held for 5 seconds to enter run mode.

The ignition mode switch has two LEDs that indicate the vehicle power mode. When the vehicle is in the off mode, both LEDs will be off. Pressing the ignition mode switch button once, without the brake pedal applied, will enter the accessory mode and the amber LED will illuminate. Pressing the ignition mode switch button a second time or pressing and holding the ignition mode switch, without the brake pedal applied, will enter the run mode and the green LED will illuminate. With the ignition off and the brake pedal applied, pressing the ignition mode switch button once, the vehicle will enter run/start mode and the green LED will illuminate. This will start the engine.

The keyless entry control module supplies the ignition mode switch a constant B+ signal on the ignition switch run signal circuit. The keyless entry control module monitors this signal to determine the igniting mode. When the ignition mode switch is not pressed, voltage on the signal circuit is pulled down through two resistors in the switch. When the ignition mode switch is pressed, voltage on the signal circuit is pulled down through only one resistor, changing the voltage seen at the keyless entry control module and indicating that the ignition mode switch is pressed.