If any of the following is detected, the ABS warning light remains on.

Refer to the CAN communication system (for LHD: , for RHD: ).

The solenoid relay is built into the master cylinder solenoid.

This relay supplies power to each solenoid. If the initial check is OK, after the ignition switch is turned to ON, the relay turns on.

The brake fluid level warning switch (brake master cylinder reservoir sub-assembly) sends the appropriate signal to the skid control ECU (master cylinder solenoid) when the brake fluid level drops.

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU (master cylinder solenoid). These signals are used for brake control.

Check with the customer to determine if frequent braking has been performed.

The skid control ECU (master cylinder solenoid) measures the speed of each wheel by receiving signals from the speed sensor. These signals are used for recognizing that all 4 wheels are operating properly. Therefore, all wheel signals must be equal.

The skid control ECU (master cylinder solenoid) has an open detection circuit, which stores this DTC when detecting an open in the stop light switch input line or the ground line of the stop light switch circuit with the stop light switch off (brake pedal not depressed).

The skid control ECU (master cylinder solenoid) receives signals from the deceleration sensor.

The DTCs are also stored when the calibration has not been completed.

Refer to DTCs C1421, C1423 and C1424 ().