PRECAUTION [DSC/RSC]

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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.

Warning lights that may illuminate and/or flash | Condition under which the light may illuminate | Conditions under which the light will go out | ABS, EBD, TCS, DSC, and RSC control
--- | --- | --- | ---
• ABS warning light • BRAKE system warning light • DSC indicator light • TCS OFF light | Under any of the following conditions: • When the front wheels are jacked up, stuck, or placed on a chassis roller, and only the front wheel ABS wheel speed sensors are spun for 20 s 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: Disables control. • EBD: 1. Disable control, in cases where the light may illuminate, only when DSC/RSC HU/CM detects that wheel speed sensors determine that two or more wheels are malfunctioning. 2. Enables control, if wheel speed sensors determine three or more wheels are functioning correctly. • TCS: Disables control. • DSC: Disables control. • RSC: Disables 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/RSC HU/CM ignition terminal drops below approx. 10 V. | Battery voltage rises above approx. 10 V. | ABS: Disables control. EBD: Enables control. TCS: Disables control. DSC: Disables control. RSC: Disables control.
• Brake system warning light | Brake fluid amount is low. | Brake fluid level is within the specification. | ABS: Enables control. EBD: Enables control. TCS: Enables control. DSC: Disables control. RSC: Disables control.

2. Precautions during servicing of DSC/RSC

The DSC/RSC is composed of electrical and mechanical parts. It is necessary to categorize malfunctions as being either electrical or hydraulic when performing troubleshooting.

  (1) 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/RSC 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/RSC 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/RSC 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.
      Warning
      • If the DSC/RSC sensor initialization procedure is not completed, it could result in an unexpected accident due to the DSC/RSC being inoperative. Therefore, after the DSC/RSC HU/CM or SAS control module is replaced, always perform the DSC/RSC sensor initialization procedure to ensure proper DSC/RSC operation. (See DSC/RSC SENSOR INITIALIZATION PROCEDURE.)
    • To protect the control module, make sure the ignition is off before connecting or disconnecting the control module connector.
      Note
      • The SAS control module detects and send to DSC/RSC HU/CM following signals:
        ― Yaw rate sensor signal
        ― Low-G (XY) sensor signal (Lateral accelerometer signal, Longitudinal acceleration plausibility)
        ― Roll rate sensor signal

  (2) 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/RSC component or the conventional brake system.
    • The hydraulic unit contains delicate mechanical parts. If foreign material gets into the component, the DSC/RSC 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/RSC does not. Make sure foreign material does not enter when servicing the DSC/RSC (e.g. brake fluid replacement, pipe removal).

Intermittent Concern Troubleshooting

Vibration method

  • If a malfunction occurs or becomes worse while driving on a rough road or when the engine is vibrating, perform the following steps.

  Note
  • There are several reasons why vehicle or engine vibration could cause an electrical malfunction. Inspect the following:
    ― Connectors not fully seated.
    ― Wire harnesses not having full play.
    ― Wires laying across brackets or moving parts.
    ― Wires routed too close to hot parts.
  • An improperly routed, improperly clamped, or loose harness can cause wiring to become pinched between parts.
  • The connector joints, points of vibration, and places where wiring harnesses pass through the firewall, body and other panels are the major areas to be inspected.

Inspection method for switch and/or sensor connectors or wires

1. Connect the M-MDS (IDS) to the DLC-2.

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2. Turn the ignition switch to the ON position (engine off).

  Note
  • If the engine starts and runs, perform the following steps at idle.

3. Access PIDs for the switch you are inspecting.

4. Turn the switch on manually.

5. Slightly shake each connector or wiring harness vertically and horizontally while monitoring the PID.

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  • If the PID value is unstable, inspect for poor connection.

Inspection method for sensors

1. Connect the M-MDS (IDS) to the DLC-2.

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2. Turn the ignition switch to the ON position (engine off).

  Note
  • If the engine starts and runs, perform the following steps at idle.

3. Access PIDs for the switch you are inspecting.

4. Vibrate the sensor slightly with your finger.

  • If the PID value is unstable or a malfunction occurs, inspect for poor connection and/or poorly mounted sensor.

Connector terminal inspection method

1. Inspect the connection of each female terminal.

2. Insert the male terminal to the female terminal and inspect the female terminal for looseness.

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