Brake Pedal Switch

KV6 – ROW The ABS ECU (C0500 on 01MY vehicles, C0501 on 02MY vehicles) provides a road wheel speed signal to the ATCU (C0932) via the CAN BUS on YN (low) and YB (high) wires. This information is relayed to the ECM (C0371) via the CAN BUS on YN (low) and YB (high) wires.

For more information on the CAN BUS, refer to the Communication Databuses section of the System Description and Operation Workshop manual.

Brake Pedal Switch

The brake pedal switch is a double contact mechanical switch, mounted at the top of the brake pedal adjacent the brake pedal sensor. The switch (C0075) is provided an ignition feed from fuse 2 of the passenger compartment fuse box (C0580) on a G wire. When the brake pedal is at rest, the switch (C0075) provides a feed to the ABS ECU (C0501) on a GR wire. When the brake pedal is pressed, the switch (C0075) informs the ABS ECU (C0501) by providing a feed on a GP wire.

When the brake pedal is pressed, the switch (C0075) also provides a feed to the following on GP wires:

The LH brake lamp (C0121). The RH brake lamp (C0125). The Centre High Mounted Stop Lamp (CHMSL) (C0613).

For more information on brake lamp operation, refer to the Brake and Reverse Lamps section of this manual.  BRAKE AND REVERSE LAMPS.

Accelerometer

The accelerometer is mounted beneath the centre console adjacent the handbrake, and provides the ABS ECU additional information regarding vehicle motion. The ABS ECU (C0501) provides a feed to the accelerometer (C1220) on a Y wire. The sensor (C1220) returns a vehicle acceleration/deceleration signal to the ABS ECU (C0501) on an R wire.

The accelerometer (C1220) is provided an earth path via the ABS ECU (C0501) on a U wire.

Brake Fluid Level Switch

The ABS ECU (C0501) provides a feed to the brake fluid level switch (C0026) on a BW wire. The switch is closed when the correct amount of brake fluid is present in the brake fluid reservoir. The switch (C0026) is earthed on a B wire. If the brake fluid level drops below the recommended level, the switch contacts open. When the ABS ECU registers the switch opening, it informs the instrument pack to illuminate the brake fluid warning lamp via the CAN-BUS.

For more information on warning lamp operation, refer to the Instruments section of this manual.  INSTRUMENTS.