Symptom Troubleshooting - Dynamic Stability Control (DSC): Precaution: Notes

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

PRECAUTION

Warning lights/Indicator lights that may illuminate	Cases in which the light may illuminate	Conditions in which the light will go out	ABS, EBD, TCS and DSC control
ABS warning light Brake system warning light TCS/DSC indicator light	Only the front wheels rotate under the following condition while jacked up, stuck, or on the chassis dynamometer: Detected at a vehicle speed of 20 km/h {12 mph} or more.	After turning off the ignition once and then restarting the engine, the vehicle is driven at 10km/h {6.2 mph} or more, and then normal operation is verified.	ABS: Cuts control. EBD: Control disabled Wheel speed sensor malfunction in two wheels or more is detected Control enabled Wheel speed sensors in three wheels or more are normal DSC: Cuts control.
	Parking brake is not fully released while driving.
	Brake drag.
	Sudden acceleration/deceleration.
	Left/right or front/rear tires are different. (Size, radius, tire pressure, or wear is other than that listed on tire label.)
	Battery voltage at DSC HU/CM terminal of voltage source (system power supply) drops below about 9.5 V.	Battery voltage rises above about 9.5 V.	ABS: Cuts control. EBD: Operates control. DSC: Cuts control.
Brake system warning light	Brake fluid amount is low.	Brake fluid level is within the specification.	ABS: Operates control. EBD: Operates control. DSC: Operates control.

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.

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 TCS/DSC indicator light and/or TCS OFF indicator light will come on when there is a problem in the electrical system. Also, past and present malfunctions are recorded in the control module. This function can find malfunction 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 malfunction, 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 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 the no DTC has been 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 off even when the ignition is switched ON. 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 off, and then clear the DTC.

CAUTION:

When any DSC HU/CM (brake fluid pressure sensor) or SAS control module (yaw rate sensor, low-G sensor) are replaced, always perform the initialization procedure to insure proper DSC operation.
To protect the control module, make sure the ignition is switched off before connecting or disconnecting the control module connector.
When repairing, if the DSC related connectors are disconnected and the ignition is switched ON, the control module will mistakenly detect a fault and record it as a malfunction.

Malfunctions in hydraulic system

Symptoms of a hydraulic system malfunction are similar to those of a conventional brake malfunction. However, it is necessary to determine if the malfunction is in a DSC component or the conventional brake system.
The hydraulic unit contains delicate mechanical parts. If foreign matter 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 matter does not penetrate the hydraulic unit when servicing the DSC (e.g. brake fluid replacement, pipe removal).