Steering Wheel Controls

Steering Wheel Controls Components
The Steering Wheel Controls consist of several components. They include the following:

^ Steering Wheel Radio and Heating-Ventilation-Air Conditioning (HVAC) Switches
^ Supplemental Inflatable Restraint (SIR) Coil Assembly
^ Steering Wheel Radio and HVAC Control Interface Module

Steering Wheel Radio and HVAC Switches
The Steering Wheel Switches control radio power, volume, station frequency, blower speed, and set temperature. These switches are actually a ladder network consisting of the switches and a series of resistors. The ladder network is arranged so that each switch has a different resistance. This allows a different voltage output to the Interface Module for each switch pressed.

SIR Coil Assembly
The SIR Coil Assembly contains four wires used by the Steering Wheel Controls. This allows voltages to be sent from the Steering Wheel Switches to the Interface Module while the Steering Wheel is being turned.

Steering Wheel Radio and HVAC Control Interface Module
The Interface Module receives the different voltages from the Steering Wheel Switches and transforms these voltages into messages to be output to the EEC Data line. Theses messages then go to the Radio, Heater and A/C Control Assembly, Passenger Climate Control Assembly (if equipped), Compact Disc Player (if equipped), and the HVAC Programmer where the requests are performed.