Mazda 6. Manual - part 251

P–60

ON-BOARD DIAGNOSTIC (ABS/TCS) 

Diagnostic procedure

STEP

INSPECTION

ACTION

1

VERIFY OTHER DTC HAS BEEN RECORDED

• Have DTCs related to solenoid valve, pump 

motor, or pump motor relay been stored?

Yes

Go to applicable DTC inspection.

No

Go to next step.

ON-BOARD DIAGNOSTIC (ABS/TCS) 

P–61

P

2

VERIFY IF CURRENT CONCERNED INPUT 
SIGNAL STATUS IS INTERMITTENT OR 
CONSTANT

• Turn ignition key to OFF.

• Connect WDS or equivalent to DLC-2.

• Start engine and drive vehicle.

• Access LF_WSPD, LR_WSPD, RF_WSPD 

and RR_WSPD using WDS or equivalent

• Do vehicle speeds correspond approximately 

to the four PIDs above?

Yes

Go to Step 8.

No

If there is a difference in speed of four wheels: Go to next 
step.
If any wheel speed is 0 km/h {0 mph}: Go to Step 4.

3

INSPECT WHEEL-SPEED SENSOR OUTPUT 
PULSE

• Start engine and drive vehicle.

• Inspect output voltage pattern using an 

oscilloscope.

Yes

Go to Step 9.

No

Go to Step 6.

• Is output voltage pattern okay?

4

INSPECT ABS WHEEL-SPEED SENSOR 
CIRCUIT FOR SHORT TO GROUND

• Turn ignition key to OFF.

• Disconnect ABS (ABS/TCS) HU/CM and 

wheel-speed sensor connectors.

• Inspect continuity between suspected sensor 

terminal(s) of ABS (ABS/TCS) HU/CM 
connector (harness side) and ground(s).
— RF wheel-speed sensor: G—ground
— LF wheel-speed sensor: I—ground
— RR wheel-speed sensor: A—ground
— LR wheel-speed sensor: C—ground

• Is there continuity?

Yes

Repair or replace harness for short to ground circuit 
between ABS (ABS/TCS) HU/CM and ABC wheel-sped 
sensor, then go to Step 9.

No

Go to next step.

5

INSPECT WHEEL-SPEED SENSOR

• Turn ignition key to OFF.

• Disconnect suspected wheel-speed sensor 

connector(s) and inspect resistance between 
wheel-speed sensor terminal(s) (part side).

• Is resistance within 1.3—1.7 kilohm?

Yes

Go to next step.

No

Replace wheel-speed sensor(s), then go to Step 9.

6

INSPECT SENSOR ROTOR CLEARANCE

• Jack-up vehicle and support it with safety 

stands.

• Remove suspected wheel(s).

• Inspect clearance between wheel-speed 

sensor and sensor rotor.

• Is clearance within 0.3—1.1 mm {0.012—

0.043 in}?

Yes

Go to next step.

No

Replace wheel-speed sensor(s), then go to Step 9.

7

INSPECT SENSOR ROTOR FOR DAMAGE

• Jack-up vehicle and support it with safety 

stands.

• Remove suspected wheel(s).

• Visually inspect sensor rotor for missing, 

deformed and obstructed teeth.
Number of teeth: 44

• Is sensor rotor okay?

Yes

Go to next step.

No

Replace sensor rotor, then go to Step 9.

STEP

INSPECTION

ACTION

P–62

ON-BOARD DIAGNOSTIC (ABS/TCS) 

End Of Sie

DTC C1186, C1266

A6E697567650W12

Caution

• When attaching the tester lead to the ABS (ABS/TCS) HU/CM harnesses connector the SST (49 

G066 001) must be used. (See 

P–29 ABS (ABS/TCS) HU/CM INSPECTION

.)

8

INSPECT ABS (ABS/TCS) HU/CM 
OPERATION

• Perform ABS (ABS/TCS) HU/CM system 

inspection.
(See 

P–27 ABS (ABS/TCS) HU/CM 

SYSTEM INSPECTION

)

• Is it okay?

Yes

Go to next step.

No

Replace ABS (ABS/TCS) HU/CM, then go to next step.

9

VERIFY TROUBLESHOOTING COMPLETED

• Make sure to reconnect all disconnected 

connectors.

• Clear DTC from memory.

See 

P–46 Clearing DTCs Procedures

• Start engine and drive vehicle at 10 km/h 

{6.2 mph} or above.

• Gradually slow down vehicle and stop.

• Is same DTC present?

Yes

Replace ABS (ABS/TCS) HU/CM, then go to next step.

No

Go to next step.

10

VERIFY AFTER REPAIR PROCEDURE

• Is there any other DTC present?

Yes

Go to applicable DTC inspection.

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

DTC

C1186, C1266

Fail-safe relay

DETECTION 

CONDITION

• C1186: 

— Fail-safe relay in ABS (ABS/TCS) HU/CM stuck OFF when ignition switch is turned ON, fail-safe 

relay ON is commanded.

• C1266: 

— Fail-safe relay in ABS (ABS/TCS) HU/CM stuck ON when ignition switch is turned ON, fail-safe relay 

OFF is commanded.

POSSIBLE 

CAUSE

• Malfunction of fuse (ABS 60 A)

• Open circuit in harness between ABS (ABS/TCS) HU/CM terminal AA and battery positive terminal

• Open or short of fail-safe relay in ABS (ABS/TCS) HU/CM

• Stuck fail-safe relay in ABS (ABS/TCS) HU/CM

ON-BOARD DIAGNOSTIC (ABS/TCS) 

P–63

P

Diagnostic procedure

End Of Sie

DTC C1194, C1198, C1210, C1214, C1242, C1246, C1250, C1254

A6E697567650W13

Diagnostic procedure

STEP

INSPECTION

ACTION

1

INSPECT ABS FUSE CONDITION

• Is ABS fuse (60 A) okay?

Yes

Go to next step.

No

Replace fuse, then go to Step 4.

2

INSPECT FAIL-SAFE RELAY POWER 
SUPPLY CIRCUIT FOR OPEN CIRCUIT

• Turn ignition key to OFF.

• Disconnect ABS (ABS/TCS) HU/CM 

connector.

• Connect SST (adapter harness) to ABS (ABS/

TCS) HU/CM connector (harness side only).

• Turn ignition key to ON (engine OFF).

• Measure voltage between ABS (ABS/TCS) 

HU/CM terminal AA (harness side) of SST 
and ground.

• Is voltage B+?

Yes

Go to next step.

No

Repair or replace harness for open circuit between battery 
positive terminal and ABS (ABS/TCS) HU/CM terminal AA, 
then go to Step 4.

3

VERIFY FAIL-SAFE OPERATION

• Turn ignition key to OFF.

• Remove SST (adapter harness) and connect 

all disconnected connectors.

• Connect WDS or equivalent to DLC-2.

• Turn ignition key to ON (engine OFF).

• Access ABS_VOLT using WDS or 

equivalent.

• Does fail-safe relay operate?

Yes

Go to next step.

No

Replace ABS (ABS/TCS) HU/CM, then go to next step.

4

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.

5

VERIFY AFTER REPAIR PROCEDURE

• Is there any other DTC present?

Yes

Go to applicable DTC inspection.

No

Troubleshooting completed.

DTC

C 1210
C 1214
C 1194
C 1198
C 1246
C 1254
C 1242
C 1250

RF pressure reduction solenoid valve
RF pressure retention solenoid valve
LF pressure reduction solenoid valve
LF pressure retention solenoid valve
RR pressure reduction solenoid valve
RR pressure retention solenoid valve
LR pressure reduction solenoid valve
LR pressure reduction solenoid valve

DETECTION 

CONDITION

• Solenoid monitor signal does not track in response to solenoid ON/OFF command.

POSSIBLE 

CAUSE

• Open, short to power, or short to ground circuit in ABS (ABS/TCS) HU/CM

• Stuck solenoid valve in ABS (ABS/TCS) HU/CM

STEP

INSPECTION

ACTION

1

VERIFY SOLENOID VALVE OPERATION

• Turn ignition key to OFF.

• Remove SST (adapter harness) and connect 

all disconnected connectors.

• Connect WDS or equivalent to DLC-2.

• Turn ignition key to ON (engine OFF).

• Access solenoid valve(s) PIDs using WDS or 

equivalent.

• Does solenoid valve operate?

Yes

Go to next step.

No

Repair ABS (ABS/TCS) HU/CM, then go to next step.

2

VERIFY TROUBLESHOOTING COMPLETED

• Clear DTC from memory.

(See 

P–46 Clearing DTCs Procedures

)

• Start engine and drive vehicle at 10 km/h 

{6.2 mph} or above.

• Gradually slow down and stop vehicle.

• Is same DTC present?

Yes

Replace ABS (ABS/TCS) HU/CM, then go to next step.

No

Go to next step.

3

VERIFY AFTER REPAIR PROCEDURE

• Is there any other DTC present?

Yes

Go to applicable DTC inspection.

No

Troubleshooting completed.