Circuit/System Description

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

The driver information center (DIC) switch is a multiplexed switch. Battery power is provided to the DIC switch via the instrument panel cluster (IPC) with the DIC switch signal circuit pulled up to battery voltage in the IPC. The IPC also provides the DIC switch with a ground reference. The switch input to the IPC is pulled low or grounded when a switch is activated. The DIC switch is a momentary contact switch that connects a series of resistors in a resistor ladder format. The IPC monitors the DIC switch signal circuit to determine the DIC switch inputs. Each switch state - Set/Reset, Trip/Fuel, Vehicle Information, Personalization, INFO UP, INFO DOWN - corresponds to a certain resistance value. The IPC determines the switch pressed by the voltage drop across the resistors. A stuck switch or a short to battery sets a DTC.

The Trip/Fuel switch is monitored on a separate circuit provided by the IPC. The Trip/Fuel switch signal circuit is monitored for a stuck switch but not a short to battery.