Mazda 6. Manual - part 260

P–96

ON-BOARD DIAGNOSTIC (DYNAMIC STABILITY CONTROL) 

DTC U2021

A6E697367650W22

Note

• To warm up the engine completely, idle the engine and wait for more than 5 minutes.

Diagnostic procedure

End Of Sie

DTC

U2021

Engine coolant temperature

DETECTION 

CONDITION

• After engine is warmed up, engine coolant temperature is 0 °C {32 °F} or less, and TCS operation is 

inhibited by PCM.

POSSIBLE 

CAUSE

• System is normal. When engine coolant temperature rises, TCS operation is executed by PCM.

STEP

INSPECTION

ACTION

1

CHECK WHETHER ENGINE HAS WARMED 
UP

• Has engine warmed up?

Yes

Go to next step.

No

Warm up the engine.
If DSC OFF light goes out, system is normal.

2

VERIFY THAT MALFUNCTION SYMPTOM 
OCCURS AFTER ENGINE IS WARMED UP

• Warm up the engine.

• Is DSC indicator light also illuminated and 

DTC C1119 obtained?

Yes

Go to DTC C1119 chart.

No

If DSC OFF light goes out, system is normal.
If DSC OFF light does not go out, go to next step.

3

VERIFY TROUBLESHOOTING COMPLETED

• Clear DTC from memory.

(See 

P–46 Clearing DTCs Procedures

)

• Is same DTC present?

Yes

Replace DSC HU/CM, then go to next step.

No

Go to next step.

4

VERIFY AFTER REPAIR PROCEDURE

• Is there any other DTC present?

Yes

Go to applicable DTC inspection.

No

Troubleshooting completed.

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL) 

P–97

P

SYSTEM WIRING DIAGRAM

A6E699067650W01

ABS (ABS/TCS)

.

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL)

A6E6921T001

1

IG switch

2

SUS  15  A  fuse

3

ABS 60 A fuse

4

Meter

5

ABS warning light

6

Brake system warning light

7

TCS OFF light

8

TCS indicator light

9

CAN  driver

10

Brake light

11

Cruise actuator

12

TCS OFF switch

13

DLC-2

14

CAN-H

15

CAN-L

16

ABS Wheel-speed sensor

17

Battery

18

Brake switch

19

Audio unit, Wiper and washer switch, Car-navigation 
unit, Auto leveling control unit

P–98

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL) 

DSC

.

A6E6920T005

1

IG switch

2

SUS  15A  fuse

3

ABS 60 A fuse

4

Meter

5

ABS warning light

6

Brake system warning light

7

DSC OFF light

8

DSC indicator light

9

CAN  driver

10

Battery

11

Cruise actuator

12

DSC OFF switch

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL) 

P–99

P

End Of Sie

FOREWORD

A6E699067650W02

• Before performing the steps in Symptom Troubleshooting, perform the On-board Diagnostic Inspection. To 

check the DTC, follow the DTC Inspection steps.

End Of Sie

PRECAUTION

A6E699067650W03

Vehicles with ABS/TCS

1. The ABS warning light, BRAKE system warning light, TCS indicator light and/or TCS OFF light illuminate even 

when the system is normal.

*

1 : In cases where the light may illuminate, only when ABS/TCS HU/CM detects that speed sensor of rear wheel 

is malfunctioning.

*

2 : If battery voltage drops below 9 V while vehicle speed is greater than 6 km/h{3.7mph}, ABS HU/CM records 

DTC B1318.

13

DLC-2

14

CAN-H

15

CAN-L

16

Wheel-speed sensor

17

Combine sensor

18

Steering angle sensor

19

Brake switch

20

Brake light

21

Back-up light switch (MTX only)

22

Back-up light

23

Audio unit, Wiper and washer switch, 
Car-navegation unit, Auto leveling control unit

Warning lights that may 
illuminate and/or flash

Cases in which the light may 
illuminate

Conditions in which the 
light will go out

ABS, EBD, TCS and DSC 
control

Any or all the following light(s) 
illuminate:

• ABS warning light

• BRAKE system warning 

light(

*1

)

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 more than 60 
seconds.

After turning ignition switch 
OFF, vehicle is driven at 
speed greater than 10 km/h 
{6.2 mph} and normal 
operation is confirmed.

• ABS: Cuts control.

• EBD: 

1. Cuts control, in cases 

where the light may 
illuminate, only when ABS 
CM detects that a wheel 
speed sensor determines 
that more than the two rear 
wheels are malfunctioning.

2. Operates control, if wheel 

speed sensor determines 
that more than 3 wheels 
are functioning correctly.

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.)

All the following lights 
illuminate:

• ABS warning light

• BRAKE system warning 

light

Battery voltage at ABS-TCS 
HU/CM ignition terminal Z 
drops below about 9 to 10 
V.(

*2

)

Battery voltage rises abobe 
about 10 V.
(Only BRAKE system warning 
light goes out.)

ABS: Operates control.
EBD: Operates control.