ABS Indicator Light
- If the system is OK, the ABS indicator light goes off two seconds after turning the ignition switch ON (II) without starting the engine. After starting the engine, the ABS indicator light comes on again and goes off after two seconds. This occurs because the ABS control unit is activated by the IG2 power source.
- The ABS indicator light comes on when the ABS control unit detects a problem in the system. However, even though the system is normal, the ABS indicator light can come on, too, under the following conditions. To determine the actual cause of problem, question the customer about the problem, taking the following conditions into consideration.
- Signal disturbance
- Wheel spin
- Only drive wheels rotate
- Battery voltage fluctuates
- When a problem is detected and the ABS indicator light comes on, the indicator light can stay on until the ignition switch is turned off, or it can automatically go off, depending on the mode.
- Light stays on until the ignition switch is turned off: When the system is in the system down mode.
- Light automatically goes off: When the system is in the control inhibition mode. (refer to symptom-to-system chart)
- The ABS indicator light stays on when the system is reactivated without erasing the DTC, but it goes off after starting the vehicle.
When the wheel sensor system is faulty and the ABS indicator light comes on, the algorithm of the system automatically turns off the ABS indicator light after the wheel speed signal returns to the normal speed. While, when the DTC is erased, the CPU is reset and the ABS indicator light goes off when the system checked out normal by the initial diagnosis. Therefore, test-drive the vehicle after servicing the wheel sensor system, and be sure that the ABS indicator light does not come on.
- When the ABS control unit outputs battery voltage to gauge assembly, the ABS indicator light goes off.