Chevrolet Spark manuals

Mazda CX-5 Service & Repair Manual: DSC HU/CM

Outline

DSC HU Part Purpose/Function

DSC HU Part Construction

Function of main component parts

Part name

Function

Inlet solenoid valve

  • Adjusts the fluid pressure in each brake system according to DSC HU/CM signals.

Outlet solenoid valve

  • Adjusts the fluid pressure in each brake system according to DSC HU/CM signals.

Stability control solenoid valve

  • Switches the brake hydraulic circuits during and according to normal braking, ABS and EBD control, TCS control, DSC control, and brake assist control.

Traction control solenoid valve

  • Switches the brake hydraulic circuits during and according to normal braking, ABS and EBD control, TCS control, DSC control, and brake assist control.

Reservoir

  • Temporarily stores brake fluid from the caliper piston to ensure smooth pressure reduction during ABS and EBD control, TCS control, and DSC control.

Pump

  • Returns the brake fluid stored in the reservoir to the master cylinder during ABS and DSC control.

  • Increases brake fluid pressure and sends brake fluid to each caliper piston during TCS control and DSC control.

Pump motor

  • Operates the pump according to DSC HU/CM signals.



DSC HU Part Operation

During normal braking

Solenoid valve operation table

Traction control solenoid valve

Stability control solenoid valve

Inlet solenoid valve

Outlet solenoid valve

Pump motor, pump

LF?RR

RF?LR

LF?RR

RF?LR

LF

RF

LR

RR

LF

RF

LR

RR

OFF (open)

OFF (closed)

OFF (open)

OFF (closed)

Stopped


Hydraulic Circuit Diagram


During ABS and EBD control

Solenoid valve operation table

Traction control solenoid valve

Stability control solenoid valve

Inlet solenoid valve

Outlet solenoid valve

Pump motor, pump

LF?RR

RF?LR

LF?RR

RF?LR

LF

RF

LR

RR

LF

RF

LR

RR

During pressure increase mode

OFF (open)

OFF (closed)

OFF (open)

OFF (closed)

Stopped

During pressure maintain mode

OFF (open)

OFF (closed)

ON (closed)

OFF (closed)

Stopped

During pressure reduction mode

OFF (open)

OFF (closed)

ON (closed)

ON (open)

Operating


Hydraulic Circuit Diagram


During DSC control (to suppress oversteer tendency) and TCS control

Solenoid valve operation table

Traction control solenoid valve

Stability control solenoid valve

Inlet solenoid valve

Outlet solenoid valve

Pump motor, pump

LF?RR

RF?LR

LF?RR

RF?LR

LF

RF

LR

RR

LF

RF

LR

RR

During pressure increase mode

OFF

(open)

ON

(closed)

OFF (closed)

ON

(open)

OFF

(open)

ON

(closed)

OFF

(open)

OFF (closed)

Operating

During pressure maintain mode

OFF

(open)

ON

(closed)

OFF (closed)

OFF

(open)

ON

(closed)

OFF

(open)

OFF (closed)

Stopped

During pressure reduction mode

OFF

(open)

ON

(closed)

OFF (closed)

OFF

(open)

ON

(closed)

OFF

(open)

OFF

(closed)

ON

(open)

OFF

(closed)

Operating


Hydraulic Circuit Diagram


During DSC control (to suppress understeer tendency)

Solenoid valve operation table

Traction control solenoid valve

Stability control solenoid valve

Inlet solenoid valve

Outlet solenoid valve

Pump motor, pump

LF?RR

RF?LR

LF?RR

RF?LR

LF

RF

LR

RR

LF

RF

LR

RR

During pressure increase mode

OFF

(open)

ON

(closed)

OFF

(closed)

ON

(open)

OFF

(open)

ON

(closed)

OFF

(open)

OFF (closed)

Operating

During pressure maintain mode

OFF

(open)

ON

(closed)

OFF (closed)

OFF

(open)

ON

(closed)

OFF

(open)

OFF (closed)

Stopped

During pressure reduction mode

OFF

(open)

ON

(closed)

OFF (closed)

OFF

(open)

ON

(closed)

OFF

(open)

OFF

(closed)

ON

(open)

OFF

(closed)

Operating


Hydraulic Circuit Diagram


DSC CM Part Function

Function table


Function name

Contents

ABS control function

  • Controls brake fluid pressure when braking to maintain directional stability, ensure steerability, and reduce stopping distance.

Electronic brakeforce distribution (EBD) control function

  • Constantly controls proper distribution of brake fluid pressure to the front and rear wheels according to vehicle load, road surface, and vehicle speed conditions to prevent early lock-up of the rear wheels.

TCS control function

  • Controls traction to within the road surface friction limit and according to road and driving conditions to improve starting and acceleration performance, and safety.

DSC control function

  • Suppresses strong over-steer and under-steer tendencies when turning by controlling engine output and braking of each wheel to assure driving safety.

Roll over mitigation (ROM) control function

  • Suppresses vehicle attitude due to overspeed during evasive steering or cornering by controlling engine speed and wheel braking to improve vehicle stability during cornering.

Brake assist control function

  • The brake pedal depression speed and force is calculated from the brake fluid pressure sensor signal. If it exceeds the specification, an emergency braking situation is determined and a higher amount of hydraulic pressure than the normal specified amount is generated in the hydraulic unit and supplied to each wheel based on the activation of each solenoid valve, pump motor, and pump.

  • If a condition is detected in which emergency braking is anticipated by the change in speed of the accelerator pedal position, the gap between the brake pad and disc plate is reduced to enhance the response when braking.

Hill launch assist (HLA) control function

  • For detailed information on the hill launch assist (HLA), refer to HILL LAUNCH ASSIST (HLA)..

Tire pressure monitoring system (TPMS) control function

  • For detailed information on the TPMS, refer to TIRE PRESSURE MONITORING SYSTEM (TPMS)..

CAN communication function

  • Outputs the vehicle speed signal and DSC system warning control data via CAN lines.

On-board diagnostic system

  • A function that allows important parts of the DSC control system to perform self-diagnosis. In case a malfunction occurs, the warning lights illuminate to alert the driver, and at the same time a DTC is stored in the DSC HU/CM.

  • When a malfunction is determined as a result of the on-board diagnostic test, system control is suspended or limited to prevent any dangerous situation while driving.

Automatic configuration function

  • When the ignition is switched to ON or the engine is started after the DSC HU/CM have been replaced, the DSC CM reads data from the instrument cluster via CAN communication to perform automatic configuration.


Block diagram


DSC Control
Outline While a vehicle normally turns safely in response to steering operation, there are instances when the limits of tire lateral grip is surpassed due to road surface conditions or ve ...

DSC HU/CM Inspection
1. Disconnect the DSC HU/CM connector.. 2. Connect the negative battery cable.. 3. Attach the tester lead to the DSC HU/CM wiring harness-side connector and inspect voltage, continuity, or resis ...

Other materials:

Up Switch Inspection [Fw6 A EL, Fw6 Ax EL]
Continuity Inspection NOTE: The up switch is built into the selector lever component. 1. Disconnect the negative battery cable.. 2. Remove the front console.. 3. Disconnect the selector lever component connector. 4. Verify that the continuity between selector lever component ...

Hazardous Driving
WARNING Be extremely careful if it is necessary to downshift on slippery surfaces: Downshifting into lower gear while driving on slippery surfaces is dangerous. The sudden change in tire speed could cause the tires to skid. This could lead to loss of vehicle control and an accident. When driv ...

Dashboard Under Cover Removal/Installation
1. Detach hooks A in the direction of arrow (1) shown in the figure. 2. Pull the dashboard under cover in the direction of arrow (2) while detaching pins B. 3. Remove the dashboard under cover in the direction of the arrow (3) shown in the figure while detaching the guide C. CAUTION: ...

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