Mazda Training manual - part 103

Dynamic Driving Safety Systems 

DSC 

Diagnostics 

• 

The DSC OFF indicator light can be checked as follows: 

– 

Visually inspecting the light after switching the ignition on 

– 

Using the input/output check mode for the IC 

– 

Monitoring the corresponding PID (see below) 

 

PID

Definition

Unit/Condition

TRAC_OFF

DSC OFF indicator light

ON/OFF

L2003_T02022

 

 

DSC OFF Switch 

• 

The DSC OFF switch is located in the dashboard. With this momentary switch, the driver 
can disable the DSC operation in case the vehicle is stuck, and spinning the wheels may 
help to free the vehicle. 

• 

Whenever the DSC is switched off, the DSC OFF indicator light in the IC will be 
illuminated. The DSC will automatically be switched on again, after switching the ignition 
off and on.  

 
NOTE:  Current Mazda vehicles with DSC do not feature a special switch for disabling the 

TCS function. The TCS is automatically disabled / enabled together with the DSC. 

 

 

L2003_02041 

 

1 

DSC OFF switch 

 

 

 
 

Curriculum Training 

02-71 

DSC 

Dynamic Driving Safety Systems 

Diagnostics 

• 

The DSC Off switch can be checked as follows: 

– 

Visually inspecting the DSC OFF indicator light while switching the DSC on and off 

– 

Reading out DTCs 

– 

Measuring voltage signals and resistance 

– 

Monitoring the corresponding PIDs (see below) 

 

PID

Definition

Unit/Condition

TCYC_SW

DSC Off switch

Pressed / Not pressed

L2003_T02029

 

 
NOTE:  Depending on the vehicle, a DTC might be stored in the DSC HU/CM when the DSC 

Off switch is pressed and held for more than approx. 10 s. In this case, the DSC is 
re-enabled and cannot be disabled again, unless the ignition is switched off and on 
again. 

 
 

02-72 Curriculum 

Training 

Dynamic Driving Safety Systems 

EBA 

Emergency Brake Assist 

• 

If the driver does not press the brake pedal hard enough in emgergency braking 
situations, the brake pressure is increased by the EBA (Emergency Brake Assist). The 
advantage is a significantly reduced braking distance. The EBA is available only in 
combination with ABS. 

• 

The EBA is automatically activated if the driver presses the brake pedal very fast, as he 
usually automatically does in an emergency situation. Once the system is activated, it 
applies full brake pressure to all wheels regardless of pedal pressure applied by the 
driver. Of course, the ABS ensures that no wheels lock-up and that the vehicle remains 
fully steerable.  

• 

Mazda uses two different types of EBA: 

– 

The electronically operated EBA, that is installed on Mazda6 

– 

The mechanical operated EBA, that is installed on Mazda2, Mazda3 and Mazda5 

 

Electronic EBA 

• 

The electronic EBA system is based on the DSC function, but applies brake pressure 
simultaneously for each wheel. 

• 

It uses the built-in brake fluid pressure sensor to monitor the speed at which the brake 
fluid pressure increases when the brake pedal is pressed. If the brake pedal is pressed 
faster than a specified value, the brake fluid pressure increases very fast, and the DSC 
HU/CM consequently decides to initiate EBA operation. 

• 

When the EBA operation is initiated, the DSC HU/CM increases the brake fluid pressure 
in the same way as it does for the TCS / DSC operation during pressure increase mode. 

 
NOTE:  The vehicle must be driven faster than approx. 17 km/h to initiate the electronic EBA. 

Once initiated, it is disabled when the vehicle speed is less than approx. 5 km/h or 
when the driver releases the brake pedal. 

 
 

Curriculum Training 

02-73 

EBA 

Dynamic Driving Safety Systems 

Mechanical EBA 

• 

The mechanical EBA is a function incorporated into the brake booster. It detects 
mechanically how fast the brake pedal is pressed. If it is pressed faster than a specified 
value, the system uses the brake booster to apply full brake fluid pressure. 

 

 

L2003_02042 

 

1 

Cross-sectional view 

4 

During normal braking 

2 Output 

characteristics 

5 Operation characteristics (varies 

according to pedal force) 

3 

During brake assist operation 

 

 

 
 

02-74 Curriculum 

Training