1 fault self-diagnosis, and most of the fail-safe features automotive anti-skid control system ECU fault self-diagnosis and fault insurance functions.
(1) In the normal case, when the ignition switch is in the ignition position, ECU will automatically the system following static POST: ① the ECU itself POST.
② the various wheel speed sensor, ABS actuator electrical components, such as solenoid valves the back pump motors, relays, and other short power-on self-test.
The ③ ECU monitoring the battery voltage is within the normal operating range, the brake fluid level in the brake fluid pressure accumulator storage tanks low.
In the process of self-test, the ABS warning light, ASR warning light will turn on automatically, the driver can thus check the warning lights and their line is intact. In the meantime, if the ECU did not find fault, after the end of the self-test process, the warning light will automatically turn off. The the static system self-test time normally lasts only 3-5s.
2) when the vehicle speed reaches a certain value (such as equipment Bosch ABS 2S vehicles when the vehicle reaches a speed 6.5km / h later), the ECU will periodically on the wheel speed sensors, solenoid valves, and back to the pump motor and other components transient dynamic test.
(3) The ECU during the anti-skid system is in working, the working condition of the system monitored.
(4) In each of the detection process described above, when the ECU system fault, ABS warning lamp and the ASR warning lamp in the one or two will be lit continuously, ECU antiskid system will automatically turn off, so that the braking of the car at the same time actuation system to return to a traditional brake system status and fault code stored in the fault memory.
In summary, when the anti-skid system warning light is lit continuously, it indicates that the system fault has been out of work state and fault conditions in code storage memory. However, not all the fault of the system can be checked by the ECU. So, even if the system warning light is not lit continuously, but when the system is not working properly, check the anti-skid system requires a comprehensive, thorough investigation of the cause, and troubleshooting in a timely manner.
Fault code read and clear most of the anti-skid control system has a self-diagnostic function, the jumper corresponding terminal in the diagnosis Block, based on light-emitting diode flashes on the dashboard warning lights or ECU to read fault codes, and then from the maintenance manual to find out the fault code on behalf of the fault condition, the computer decoder can also be used to directly read the fault codes. There are some anti-skid system, can only use the computer decoder to read fault codes, such as General Motors Corp. in its production of some models are equipped with ABS VI system, you can only use the decoder to read stored in the ECU the fault code.
Different anti-skid control system read fault codes, warning lights or flashing light-emitting diodes and counting method is not the same, should maintenance manual for the fault code on behalf of the fault condition. Below to Toyota TOYOTA car lines as an example to illustrate the fault code read and clear method.