Antilock Brakes / Traction Control Systems: Service Precautions

PRECAUTION

1. The ABS warning light and/or brake system warning light and/or DSC indicator light and/or TCS OFF light illuminate even when the system is normal.





2. Precautions during servicing of DSC
The DSC is composed of electrical and mechanical parts. It is necessary to categorize malfunctions as being either electrical or hydraulic when performing troubleshooting.
a. Malfunction in electrical system

- The control module has an on-board diagnostic function. With this function, the ABS warning light and/or brake system warning light and/or DSC indicator light and/or TCS OFF light will illuminate when there is a problem in the electrical system.
Also, past and present malfunctions are in the control module. This function can find malfunctions that do not occur during periodic inspections. Connect the M-MDS to the DLC-2, the stored malfunctions will be displayed in the order of occurrence. To find out the causes of DSC malfunctions, use these on-board diagnostic results.
- If a malfunction occurred in the past but is now normal, the cause is likely a temporary poor connection of the wiring harness.
The control module usually operates normally. Be careful when searching for the cause of malfunction.
- After repair, it is necessary to clear the DTC from the control module memory.
Also, if the DSC related parts have been replaced, verify that no DTC is displayed after repairs.
- After repairing the ABS wheel-speed sensor or ABS sensor rotor, or after replacing the control module, the ABS warning light may not go out even when the ignition switch is turned to the ON position. In this case, drive the vehicle at a speed of more than 10 km/h {6.2 mph}, make sure the ABS warning light goes out, and then clear the DTC.
- When repairing, if the DSC related connectors are disconnected and the ignition switch is turned to the ON position, the control module will mistakenly detect a fault and record it as a malfunction.

CAUTION:
- In DSC vehicles, when the DSC HU/CM, steering angle sensor, or combined sensor is replaced, perform the initialization procedure for each sensor. DSC Sensor Initialization Procedure Programming and Relearning
- To protect the control module, make sure the ignition is off before connecting or disconnecting the control module connector.

b. Malfunctions in hydraulic system

- Symptoms in a hydraulic system malfunction are similar to those in a conventional brake malfunction. However, it is necessary to determine if the malfunction is in a DSC component or the conventional brake system.
- The DSC HU/CM contains delicate mechanical parts. If foreign material gets into the component, the DSC may fail to operate. Also, it will likely become extremely difficult to find the location of the malfunction in the event that the brakes operate but the DSC does not. Make sure foreign material does not enter when servicing the DSC (e.g.brake fluid replacement, pipe removal).