Interface Unit

Brake Lamp Switch – 02MY Vehicles The Hall effect brake lamp switch (C0652) is provided an ignition feed from fuse 35 of the passenger compartment fuse box (C0580) on a W wire. The switch (C0652) is earthed on a B wire. When the brake pedal is in its normal position, the switch provides the cruise control interface unit (C1959) a low voltage (between approximately 0V and 2V) on a PG wire. When the brake pedal is pressed, this voltage rises to between approximately 6V and battery voltage. When the interface unit registers this rise in voltage, it suspends cruise control operation.

The brake lamp switch (C0652) also provides a brake pedal status signal to the cruise control interface unit (C1959) on a GR wire.

Interface Unit

The interface unit (C1959) provides a feed to the cruise control ECU (C0239) on a PG wire if the following conditions exist:

The cruise control master switch is depressed. The brake pedal is not depressed. HDC is not activated. The gear selector lever is not in the park, neutral, or reverse positions. Engine speed is below 6,496 rpm.

The cruise control ECU uses the feed provided by the interface unit to enable the cruise control pump. For more details on interface unit operation, refer to the Interface Unit section below.

Interface Unit

Fuse 35 of the passenger compartment fuse box (C0580) provides an ignition feed to the interface unit (C1959) on a W wire. The interface unit is earthed on a pair of B wires, and receives inputs from a number of different components as follows:

Cruise Control Master Switch

When the cruise control master switch is depressed, it provides a feed to the interface unit (C1959) on a WY wire.

Brake Lamp Switch – 01MY Vehicles When the brake pedal is in its normal position, the switch (C0652) provides the interface unit (C1959) a low voltage (between approximately 0V and 2V) on a GR wire. When the brake pedal is pressed, this voltage rises to between approximately 6V and battery voltage.

Brake Lamp Switch – 02MY Vehicles When the brake pedal is in its normal position, the switch (C0652) provides the interface unit (C1959) a low voltage (between approximately 0V and 2V) on GR and PG wires. When the brake pedal is pressed, this voltage rises to between approximately 6V and battery voltage.