With the ignition switch in the ON position (II), fused battery voltage is provided to terminal B of the cruise control switch. The normally closed contacts of the ON switch, internal to the cruise control switch, completes the circuit to terminal C of the cruise control switch. From terminal C, the battery voltage is provided on CKT FA300 to the Engine Control Module (ECM) connector C2 terminal 42. If the brake pedal is released, fused battery voltage is provided on the cruise control release switch circuit to ECM connector C2 terminal 26. If the brake pedal is depressed, battery voltage is provided on the stoplamp switch circuit to ECM connector C2 terminal 27. A malfunction on the cruise control release switch or stoplamp switch circuits can inhibit cruise control operation. The ECM sets a DTC when a malfunction exists on the cruise control release switch circuit.

Pressing the SET/ACCEL button closes the normally open switch contacts providing fused battery voltage from terminal B to terminal D of the cruise control switch. From terminal D, the battery voltage is provided on CKT FB300 to ECM connector C2 terminal 43. Pressing the RESUME/DECEL button provides the fused battery voltage to terminal A of the switch. From terminal A, the battery voltage is provided on CKT FX500 to ECM connector C2 terminal 10.

The Electronic Brake and Traction Control Module (EBTCM) provides the vehicle speed to the ECM via the Controlled Area Network (CAN) circuits. The CAN circuits (XR12 and XY29) connect to ECM connector C2 terminals 12 and 29.

In operation, the ECM controls the throttle-valve angle with an electric throttle-valve motor. The throttle-valve motor is an integral part of the throttle position (TP) sensor. The ECM provides the voltage and ground for the throttle-valve motor. Voltage is provided from ECM connector C1 terminals 17 and 49 to terminal 4 of the TP sensor. Ground is provided at terminal 1 of the TP sensor to ECM connector C1 terminals 1 and 33.

The Accelerator Pedal Position Sensor (APP) monitors the position of the accelerator pedal and transmits this information from terminals 5 and 1 to ECM connector C2 terminals 40 and 8 respectively. The ECM processes the signal along with data transmitted from other systems (such as ABS and traction control) to calculate the control signal for the throttle-valve motor. A closed-loop control circuit ensures precise adjustment of the throttle angle in a process based on the return signals transmitted to the ECM from two potentiometers within the TP sensor. The return signals come from TP sensor terminals 5 and 6 to ECM connector C1 terminals 40 and 24 respectively.

The ECM continuously monitors all components to ensure that the system is operating properly. Because the ECM and all sensors have backup units (redundancy), the system can compare the signal pairs to verify the monitoring process.

When the cruise control is engaged and operating, the CRUISE indicator bulb in the instrument cluster is illuminated. The ECM provides the ground for the bulb from the instrument cluster connector terminal 17 on CKT XM801 to ECM connector C2 terminal 1.

Pressing the OFF button opens the normally closed switch contacts interrupting the voltage provided to ECM connector C2 terminal 42. The ECM disengages the cruise control operation when the voltage input at terminal 42 is interrupted. The previous speed setting stored in memory is not retained after pressing the OFF button.