Speed Control Switches

There are two separate switch pods that operate speed control system. The steering-wheel mounted switches provide a single multiplexed (MUX) voltage inputs to PCM for ON, OFF, SET, COAST, RESUME, ACCELERATE, TAP-UP and CANCEL modes. Based on conditions when the buttons are pushed (and released), the five voltage ranges provided to the PCM result in the following functions: ON, OFF, SET, COAST, RESUME, ACCEL, TAP-UP, TAP-DOWN COAST and CANCEL.

The PCM receives an input from the brake switch to sense whether the brake pedal has been depressed. When PCM receives the brake depressed input, it disconnects power to the speed control servo and disengages the speed control. The servo is also supplied power through the brake switch, which opens the circuit when the brake pedal is depressed. Individual switches cannot be repaired separately. If one switch fails, the entire switch module must be replaced.