Mazda 6. Manual - part 264

P–112

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL) 

4

INSPECT PID/DATA IN ABS/TCS HU/CM
Inspect the following items using WDS or 
equivalent PID/DATA monitor function.

• ABS_LAMP (ABS warning light)

• BRAKE_ LAMP (BRAKE system warning 

light)

• ABS_VOLT (power supply voltage)

Is ABS_LAMP and BRAKE_LAMP ON after 
more than 4 seconds with ignition switch on?

Yes

Go to Step 7.

No

Go to next step.

5

INSPECT ABS/TCS HU/CM IGNITION POWER 
SUPPLY SYSTEM (TERMINAL Z)
Check the voltage for PID/DATA monitor 
ABS_VOLT item.
Specification: about 10 V
Is voltage within specification?

Yes

Replace ABS/TCS HU/CM (open or short in ground circuit in 
ABS/TCS HU/CM)

No

Go to next step.

6

INSPECT BATTERY
Is battery voltage normal?

Yes

Go to next step.

No

Inspect battery and charging system.

7

INSPECT CHARGING SYSTEM
Is battery voltage normal with electrical load (A/
C, headlight, etc.) on and engine idling?

Yes

Go to Step 7.

No

Inspect charging system (drive belt tension, generator, etc.).

*

8

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM POWER SUPPLY AND ABS/TCS 
HU/CM FOR CONTINUITY
Disconnect ABS/TCS HU/CM connector.
Connect the SST (49 G066 001) (vehicle 
harness side only).
Is voltage approximately 12 V at SST 
connector terminal Z?

Yes

Go to next step.

No

Check for connection of ABS/TCS HU/CM connector 
securely.

*

9

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM GROUND FOR CONTINUITY
Turn ignition switch to LOCK.
Is there continuity between SST connector 
terminal AC and ground?

Yes

If a malfunction error message is displayed on WDS or 
equivalent in Step 1 inspection, go to next step.
If a malfunction error message is not displayed on WDS or 
equivalent in Step 1 inspection, troubleshooting is 
completed.

No

Repair wiring harness between ABS/TCS HU/CM and 
ground.

*

10

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR CONTINUITY
Is there continuity between SST connector 
terminal X and DLC-2?

Yes

Go to next step.

No

Repair wiring harness between ABS/TCS HU/CM and 
DLC-2.

11

*

INSPECT WIRING HARNESS BETWEEN 

ABS/TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR SHORT TO BATTERY
Is voltage approximately 12 V at SST 
connector terminal X?

Yes

Repair wiring harness between ABS/TCS HU/CM and 
DLC-2.

No

Go to next step.

12

*

INSPECT WIRING HARNESS BETWEEN 

ABS/TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR SHORT TO GROUND
Is there continuity between SST connector 
Terminal X and DLC-2?

Yes

Repair wiring harness between ABS/TCS HU/CM and 
DLC-2.

No

Replace ABS/TCS HU/CM (communication circuit 
malfunction in ABS/TCS HU/CM)

STEP

INSPECTION

ACTION

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL) 

P–113

P

End Of Sie

NO.7 ABS WARNING LIGHT STAYS ON MORE THAN 4 SECONDS WITH IGNITION SWITCH ON

A6E699067650W11

Diagnostic procedure

STEP

INSPECTION

ACTION

7

ABS warning light stays on more than 4 seconds with ignition switch on.

[TROUBLESHOOTING HINTS]

• ABS/TCS CM detects ABS system malfunction.

STEP

INSPECTION

ACTION

1

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR CONTINUITY AND 
SHORTS
Perform DTC inspection.
Is error message displayed regarding 
communication between ABS/TCS HU/CM and 
WDS or equivalent?

Yes

If the communication error message is displayed even after 
inspecting according to procedures displayed in the WDS or 
equivalent, go to Step 4.

No

Go to next step.

2

CHECK FOR DTCs IN ABS/TCS HU/CM
Have DTCs been recorded in memory?

Yes

Perform inspection using appropriate DTC.

No

Go to next step.

3

INSPECT PID/DATA IN ABS/TCS HU/CM
Inspect the following items using WDS or 
equivalent PID/DATA monitor function.

• ABS_LAMP (ABS warning light)

Is ABS_LAMP ON after more than 4 
seconds with ignition switch on?

Yes

Replace ABS/TCS HU/CM (open circuit or short to ground in 
ABS/TCS HU/CM).

No

Inspect instrment cluster.

*

4

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR CONTINUITY
Disconnect ABS/TCS HU/CM connector.
Connect the SST ( 49 G066 001) (vehicle 
harness side only).
Is there continuity between SST connector 
terminal X and data link connector?

Yes

Go to next step.

No

Repair wiring harness between ABS/TCS HU/CM and data 
link connector.

*

5

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR SHORT TO B+
Is voltage approximately 12V at SST connector 
terminal X?

Yes

Repair wiring harness between ABS/TCS HU/CM and data 
link connector.

No

Go to next step.

P–114

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL) 

• When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while 

doing the inspection to discover whether poor contact points are the cause of any intermittent malfunction. If 
there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly 
and undamaged.

End Of Sie

NO.8 BRAKE SYSTEM WARNING LIGHT STAYS ON MORE THAN 4 SECONDS WITH IGNITION SWITCH ON

A6E699067650W12

Diagnostic procedure

*

6

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR SHORT TO GROUND
Is there continuity between SST connector 
terminal X and ground?

Yes

Repair wiring harness between ABS/TCS HU/CM and data 
link connector.

No

Replace ABS/TCS HU/CM (communication circuit 
malfunction is ABS/TCS HU/CM).

STEP

INSPECTION

ACTION

8

BRAKE system warning light stays on more than 4 seconds with ignition switch on.  (Parking brake 
is released.)

[TROUBLESHOOTING HINTS]

• Malfunction of instrment cluster or ABS/TCS HU/CM

• Short to ground in circuit in parking brake switch and/or brake fluid level sensor

STEP

INSPECTION

ACTION

1

INSPECT BRAKE FLUID LEVEL
Is brake fluid level okay?

Yes

Go to next step.

No

Add brake fluid.

*

2

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2 ) FOR CONTINUITY AND 
SHORTS
Inspect the following items using WDS or 
equivalent PID/DATA monitor function.

• BRAKE_LAMP(BRAKE system warning 

light)

Is error message displayed regarding 
communication between ABS/TCS HU/CM and 
WDS or equivalent?

Yes

If a communication error message is displayed even after 
inspecting according to procedures displayed on WDS or 
equivalent.
Go to next step6.

No

Go to next step.

3

CHECK FOR DTCs IN ABS/TCS HU/CM 
Have DTCs been recorded in memory?

Yes

Perform inspection using appropriate DTC.

No

Go to next step.

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL) 

P–115

P

• When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while 

doing the inspection to discover whether poor contact points are the cause of any intermittent malfunction. If 
there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly 
and undamaged.

End Of Sie

4

INSPECT PID/DATA IN ABS/TCS HU/CM
Inspect (BRAKE system warning light) using 
WDS or equivalent PID/DATA monitor function.
Is BRAKE_LAMP on after more than 4 
seconds with ignition switch on?

Yes

Connect ABS/TCS HU/CM connector terminal X securely, 
then go to next step.

No

Go to step 6.

5

VERIFY WHETHER MALFUNCTION IS IN 
PARKING BRAKE SWITCH OR BRAKE FLUID 
LEVEL SENSOR, OR IN SOME OTHER PART
Disconnect the following in order:

1. Parking brake switch connector
2. Brake fluid level sensor connector

Does BRAKE system warning light go out with 
ignition switch on?

Yes

Replace parking brake switch and/or brake fluid level sensor 
(shorted on some internal part).

No

Perform the following inspections. Repair if necessary.

• Short to ground in wiring harness between instrument 

cluster ( BRAKE system warning light) and parking 
brake switch.

• Short to ground in wiring harness between instrument 

cluster (BRAKE system warning light) and brake fluid 
level sensor.

Inspect instrument cluster.

*

6

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR CONTINUITY
Disconnect ABS/TCS HU/CM connector.
Connect the SST ( 49 G066 001) (vehicle 
harness side only).
Is there continuity between SST connector 
terminal X and data link connector?

Yes

Go to next step.

No

Repair wiring harness between ABS/TCS HU/CM and data 
link connector.

*

7

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR SHORT TO B+
Is voltage approximately 12 V at SST 
connector terminal X?

Yes

Repair wiring harness between ABS/TCS HU/CM and data 
link connector.

No

Go to next step.

*

8

INSPECT WIRING HARNESS BETWEEN ABS/
TCS HU/CM AND DLC-2 (DATA LINK 
CONNECTOR-2) FOR SHORT TO GROUND
Is there continuity between SST connector 
terminal X and ground?

Yes

Repair wiring harness between ABS/TCS HU/CM and data 
link connector.

No

Replace ABS/TCS HU/CM (communication circuit 
malfunction in ABS/TCS HU/CM).

STEP

INSPECTION

ACTION