Pinpoint Test A : The Cruise Control Is Inoperative: Notes

Refer to Cruise Control for schematic and connector information.

Normal Operation and Fault Conditions 

The cruise control functionality is controlled through the brake pedal switch that is hard-wired to the PCM through a signal and return circuit, and a cruise control deactivator switch that is hard-wired to the IPC. There are 5 cruise control switches with each switch operating a specific function that uses different resistance values. The IPC sends out a reference voltage to the cruise control switches and monitors the voltage drop when a cruise control switch is pressed. The voltage drop varies depending upon the resistance of each switch, providing a specific indication to the IPC which switch is pressed.

The IPC sends a network message over the High Speed Controller Area Network (HS-CAN) to the PCM relaying the switch status and requesting cruise control operation. The stoplamp switch is an input to the PCM for the cruise control operation. When the brake pedal is applied, the normally open stoplamp switch closes and applies a voltage signal to the PCM deactivating the cruise control, if engaged. The cruise control deactivator switch is a normally closed switch that provides a ground signal to the IPC. When the brake pedal is applied, the switch opens and removes the ground signal to the IPC.

The IPC sends a network message over the HS-CAN to the PCM. This is a redundant signal to the PCM. The PCM receives both signals and compares the inputs to confirm the correct brake input sequence is received.

Diagnostic Trouble Code (DTC) Fault Trigger Conditions 

Possible Sources 

• Wiring, terminals or connectors
• Clockspring
• Digital Transmission Range (TR) sensor (automatic transaxle)
• Cruise control switch
• Cruise control deactivator switch
• Clutch pedal cruise control deactivator switch (manual transaxle)
• IPC
• PCM
• ABS module