Scheme 1
Circuit/System Description
The instrument panel module (IPM) supplies voltage to the multiple momentary contact switches and monitors the return signal. Each switch is associated to a set resistance value, when pressed a specific voltage drop occurs through a series of resistors unique to that switch. The IPM identifies the selection, then sends a serial data message that is received by the component controlled, activating the feature. If equipped with adaptive cruise control the Gap+/Gap- switches are in place of the mute/source switches and are in the same resistor ladder circuit.
The instrument panel module (IPM) supplies voltage to the multiple momentary contact switches and monitors the return signal. Each switch is associated to a set resistance value, when pressed a specific voltage drop occurs through a series of resistors unique to that switch. The IPM identifies the selection, then sends a serial data message that is received by the component controlled, activating the feature. If equipped with adaptive cruise control the Gap+/Gap- switches are in place of the mute/source switches and are in the same resistor ladder circuit.
Steering Wheel Controls Description and Operation
The steering wheel control switches duplicate the function of the primary controls of the associated component, through a network of multiple momentary contact switches and a series of resistors. The instrument panel module (IPM) supplies voltage to the switches and monitors the return signal for a specific voltage drop to occur unique to the one pressed. The IPM identifies the selection, then sends a serial data message to the component controlled by the switch and activates the feature.
This section is intended to diagnose the circuits between the IPM and the steering wheel control switches. If the primary control for the device is inoperative, refer to the appropriate section for the component the steering wheel control switch controls.
See also:
• Component Connector End Views