Mazda 6. Manual - part 358

ON-BOARD DIAGNOSTIC [CRUISE CONTROL SYSTEM] 

T–179

T

FOREWORD

A6E817266350W01

Outline

• There are two on-board diagnostic functions: Operation mode, which inspects for and indicates correct 

operation of the input signals to the control module, and condition detection mode, which indicates troubles in 
the system.

• The two functions can be done using either of the following methods:

— Verifying the flashing pattern of the cruise set indicator light in the instrument cluster.

Inspection Order

End Of Sie

INSPECTION OF DTCS FOR OPERATION MODE

A6E817266350W02

Note

• The cruise set indicator light will illuminate for 3 seconds‚ when operation mode is on.

• If the cruise set indicator light does not illuminate for 3 seconds (Operation mode is not on)‚ the following 

may be the cause of the malfunction:
— Cruise actuator ignition power supply fuse
— Cruise set indicator light power supply fuse
— Cruise control switch
— Cruise control main switch
— Clock spring for air bag system
— Print plate in instrument cluster
— Cruise set indicator light bulb
— Cruise actuator
— Open or short circuit in following wiring harnesses:

• Between cruise set indicator light and cruise actuator terminal G

• Between fuse block and cruise actuator terminal L

• Between fuse block and instrument cluster

• Between cruise actuator and clock spring

• Between clock spring and cruise control switch

— Open circuit in following wiring harnesses:

• Between cruise actuator terminal I and ground

• Between clock spring and ground

1. Turn the ignition switch to the ON position.
2. Verify that the cruise control main switch is off.

ON-BOARD DIAGNOSTIC [CRUISE CONTROL SYSTEM]

A6E8172W001

T–180

ON-BOARD DIAGNOSTIC [CRUISE CONTROL SYSTEM] 

3. Press and hold the RESUME/ACCEL switch on 

(1), and turn on the cruise control main switch (2). 
Keep the RESUME/ACCEL switch on for 3 
seconds or more after the cruise control main 
switch released. (The cruise set indicator light will 
illuminate for 3 seconds, showing that the system 
inspection has started.)

4. Operate each switch as described in the 

operation code list and note the operation code 
list pattern.

• If the cruise set indicator light does not flash, 

inspect the corresponding system area.

• If it flashes, the corresponding DTC(s) will be 

indicated and mode can be judged normal.

5. The operation mode is canceled by turning the ignition switch to LOCK position or turning off the cruise control 

main switch.

Operation Code List

Inspection of Diagnostic Trouble Codes
Foreword

• 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 harness are connected correctly and 
undamaged.

End Of Sie

A6E8172W002

Operation

DTC

Output pattern

Diagnosed circuit

Page

Turn SET/COAST switch 
on

21

Cruise control switch 
(SET/COAST switch)

(See 

T–181 

DTC 21

)

Turn RESUME/ACCEL 
switch on

22

Cruise control switch
(RESUME/ACCEL 
switch)

(See 

T–181 

DTC 22

)

Depress brake pedal

31

Brake switch

(See 

T–182 

DTC 31

)

MTX:

Depress clutch pedal

ATX:

Shift selector lever to P 

or N position

35

MTX:

Clutch switch

ATX:

TR switch

(See 

T–183 

DTC 35

)

Drive vehicle above  40 
km/h {25 mph}

37

Vehicle speed sensor

(See 

T–184 

DTC 37

)

ON-BOARD DIAGNOSTIC [CRUISE CONTROL SYSTEM] 

T–181

T

DTC 21

A6E817266350W03

Diagnostic procedure

End Of Sie

DTC 22

A6E817266350W04

Diagnostic procedure

End Of Sie

DTC 21

Cruise control switch (SET/COAST switch)

DETECTION 

CONDITION

• Resistance detected between cruise actuator connector terminal J and ground is other than 

approximately 680 ohms.

POSSIBLE 

CAUSE

• Cruise actuator malfunction

• Cruise control switch malfunction

• Clock spring malfunction

• Open circuit in wiring harness between clock spring and ground

• Open or short circuit in wiring harness between cruise actuator and clock spring

STEP

INSPECTION

ACTION

1

INSPECT SIGNAL LINE OF CRUISE 
CONTROL SWITCH POSITION

• Disconnect cruise actuator connector.

• Turn SET/COAST switch on.

• Is resistance at cruise actuator connector 

terminal J approximately 680 ohms?

Yes

Replace cruise actuator.
(See 

T–110 CRUISE ACTUATOR REMOVAL/

INSTALLATION

)

No

Go to next step.

2

INSPECT CRUISE CONTROL SWITCH

• Inspect cruise control switch.

(See 

T–116 CRUISE CONTROL SWITCH 

INSPECTION

)

• Is cruise control switch okay?

Yes

Go to next step.

No

Replace cruise control switch.
(See 

T–115 CRUISE CONTROL SWITCH REMOVAL/

INSTALLATION

)

3

INSPECT CLOCK SPRING

• Inspect clock spring.

(See 

T–126 CLOCK SPRING INSPECTION

)

• Is clock spring okay?

Yes

Go to next step.

No

Replace clock spring.
(See 

T–125 CLOCK SPRING REMOVAL/INSTALLATION

)

4

INSPECT WIRING HARNESS BETWEEN 
CLOCK SPRING AND GROUND FOR 
CONTINUITY

• Disconnect cruise control switch connector.

• Is there continuity between clock spring 

connector terminal C and ground?

Yes

Repair wiring harness. (cruise actuator—clock spring)

No

Repair wiring harness. (clock spring—ground)

DTC 22

Cruise control switch (RESUME/ACCEL switch)

DETECTION 

CONDITION

• Resistance detected between cruise actuator connector terminal J and ground is other than 

approximately 2.2 kilohms.

POSSIBLE 

CAUSE

• Cruise actuator malfunction

• Cruise control switch malfunction

INSPECTION

ACTION

INSPECT CRUISE CONTROL SWITCH

• Inspect cruise control switch.

(See 

T–116 CRUISE CONTROL SWITCH 

INSPECTION

)

• Is cruise control switch okay?

Yes

• Replace cruise actuator.

(See 

T–110 CRUISE ACTUATOR REMOVAL/

INSTALLATION

)

No

• Replace cruise control switch.

(See 

T–115 CRUISE CONTROL SWITCH REMOVAL/

INSTALLATION

)

T–182

ON-BOARD DIAGNOSTIC [CRUISE CONTROL SYSTEM] 

DTC 31

A6E817266350W05

Diagnostic procedure

DTC 31

Brake switch

DETECTION 

CONDITION

• Voltage detected at cruise actuator connector terminal C is not approximately 12 V or voltage detected 

at cruise actuator connector terminal K is not approximately 0 V.

POSSIBLE 

CAUSE

• Burnt STOP 15 A fuse

• Cruise actuator malfunction

• Brake switch and/or brake switch 2 malfunction

• Open circuit in wiring harness between STOP 15 A fuse and brake switch

• Open circuit in wiring harness between brake switch and cruise actuator terminal C

• Short circuit in wiring harness between brake switch 2 and cruise actuator terminal K

STEP

INSPECTION

ACTION

1

VERIFY WHICH BRAKE SWITCH CIRCUIT IS 
MALFUNCTIONING

• Does brake light illuminate when brake pedal 

depressed?

Yes

Go to Step 6.

No

Go to next step.

2

INSPECT STOP 15 A FUSE FOR FUSION

• Is STOP 15 A fuse okay?

Yes

Go to next step.

No

Replace fuse after inspecting and repairing wiring harness.

* 3

INSPECT WIRING HARNESS BETWEEN 
STOP 15 A FUSE AND BRAKE SWITCH FOR 
CONTINUITY

• Depress brake pedal.

• Is voltage at brake switch connector terminal 

D approximately 12 V?

Yes

Go to Step 5.

No

Go to next step.

* 4

INSPECT WIRING HARNESS BETWEEN 
STOP 15 A FUSE AND BRAKE SWITCH FOR 
CONTINUITY

• Is voltage at brake switch connector terminal 

B approximately 12 V?

Yes

Inspect brake switch.
(See 

P–8 BRAKE SWITCH INSPECTION

)

No

Repair wiring harness. (STOP 15 A fuse—Brake switch)

* 5

INSPECT WIRING HARNESS BETWEEN 
BRAKE SWITCH AND BRAKE LIGHT FOR 
CONTINUITY

• Depress brake pedal.

• Is voltage at brake light connector terminal 

(power supply side) approximately 12 V?

Yes

Inspect following electrical parts.

• Brake light bulb

• Wiring harness between brake light and ground

No

Repair wiring harness. (Brake switch—Brake light)

* 6

INSPECT WIRING HARNESS BETWEEN 
BRAKE SWITCH AND CRUISE ACTUATOR 
FOR CONTINUITY

• Depress brake pedal.

• Is voltage at cruise actuator connector 

terminal C approximately 12 V?

Yes

Go to next step.

No

Repair wiring harness. (Cruise actuator—Brake switch)