General
The ABS is a full time, four channel system that gives individual speed control to all four wheels to provide the vehicle with anti-lock braking (ABS), Electronic Traction Control (ETC), and Hill Descent Control (HDC). The systems are controlled by the ABS ECU, which is mounted on the rear of the ABS modulator. The ABS ECU also controls the front to rear brake balance by Electronic Braking force Distribution (EBD). This maximizes vehicle stability under braking.
For a detailed description of ABS, ETC HDC, and EBD, refer to CONTROL UNITS - DESCRIPTION & OPERATION of the System Description and Operation Workshop manual.
The ABS modulator uses the CAN-BUS to communicate with other ECU's to enable it to control braking more efficiently. For more information on the CAN-BUS, refer to COMMUNICATION DATA BUSES - DESCRIPTION & OPERATION of the System Description and Operation Workshop manual.
Feed from the positive battery terminal (C0192) is supplied to fusible link 1, fusible link 3, fusible link 8, and fusible 11 (C0632) on an R wire. All are located in the engine compartment fuse box.
Fusible link 8 (C0574) and fusible link 11 (C0570) provide constant battery feeds to the ABS modulator (C0501) on NK and NR wires respectively. The ABS modulator (C0501) is earthed on a pair of B wires.
Fusible link 1 is connected in series with fusible link 2, which is also located in the engine compartment fuse box. Fusible link 2 (C0571) provides a feed to the ignition switch (C0028) on an NR wire. Fusible link 3 (C0571) also provides a feed to the ignition switch (C0028) on an N wire.
When the ignition switch is turned to the 'ignition' position, current flows across the switch (C0028) to fuse 2 of the passenger compartment fuse box (C0588) on an NW wire. When in the 'ignition' position, the ignition switch (C0028) also provides a feed to fuse 6 and fuse 25 of the passenger compartment fuse box (C0588) on a G wire.
Fuse 2 of the passenger compartment fuse box (C0581) provides an ignition feed to the brake pedal switch (C0075) on a G wire. Fuse 2 also provides a feed to the HDC relay and the reverse lamp relay, which are also located in the passenger compartment fuse box.
Fuse 25 (C0582) provides an ignition feed to the ABS ECU (C0501) on a W wire. Fuse 6 (C0581) provides an ignition feed to the HDC switch (C0878) on a W wire.