Mazda 6. Manual - part 351

ON-BOARD DIAGNOSTIC [HEADLIGHT AUTO LEVELING SYSTEM] 

T–153

T

DTC B2615

A6E816467000W07

DTC B2615

Front or rear auto leveling sensors power supply system.

DETECTION 

CONDITION

Warning
• incorrect servicing of the auto leveling control unit could result in electrical shock because 

the unit is integrated with the discharge headlight control unit. Before servicing the auto 
leveling control unit, always refer to “Discharge headlight service warnings.” (See 

T–25 

DISCHARGE HEADLIGHT SERVICE WARNINGS

)

Front auto leveling sensor or rear auto leveling sensor supply voltage (5 V), which is generated by auto 
leveling control unit (main), is incorrect.

POSSIBLE 

CAUSE

• Front auto leveling sensor malfunction

• Rear auto leveling sensor malfunction

• Auto leveling control unit malfunction

• Short circuit in wiring harness between front auto leveling sensor and headlight (LH)

• Short circuit in wiring harness between rear auto leveling sensor and headlight (LH)

• Headlight (LH) malfunction

T–154

ON-BOARD DIAGNOSTIC [HEADLIGHT AUTO LEVELING SYSTEM] 

Diagnostic procedure

End Of Sie

STEP

INSPECTION

ACTION

1

INSPECT POWER SUPPLY CIRCUIT OF 

HEADLIGHT (LH)

• Disconnect headlight (LH) connector (4-pin).

• Turn the ignition switch to ON.

• Measure voltage at headlight (LH) connector 

terminal 2A.

• Is voltage approximately 5 V?

Yes

Go to next step.

No

Go to step 4.

2

INSPECT POWER SUPPLY CIRCUIT OF 

FRONT AUTO LEVELING SENSOR

• Turn the ignition switch to OFF and connect 

headlight (LH) connector (4-pin) again.

• Disconnect front auto leveling sensor 

connector (6-pin).

• Measure voltage at front auto leveling sensor 

connector terminal D.

• Is voltage approximately 5 V?

Yes

Replace front auto leveling sensor.
(See 

T–32 FRONT AUTO LEVELING SENSOR REMOVAL/

INSTALLATION

)

After replacement, clear DTC and check DTC again.

• If DTC is displayed again, go to next step.

No

Repair or replace wiring harness between front auto leveling 
sensor and headlight (LH).

3

INSPECT POWER SUPPLY CIRCUIT OF 

REAR AUTO LEVELING SENSOR

• Disconnect rear auto leveling sensor 

connector.

• Measure voltage at rear auto leveling sensor 

connector terminal D.

• Is voltage approximately 5 V?

Yes

Replace front auto leveling sensor.
(See 

T–32 REAR AUTO LEVELING SENSOR REMOVAL/

INSTALLATION

)

After replacement, clear DTC and check DTC again.

• If DTC is displayed again, go to next step.

No

Repair or replace wiring harness between rear auto leveling 
sensor and headlight (LH).

4

INSPECT HEADLIGHT (LH)

• Disconnect auto leveling control unit (main) 

connector (20-pin) and headlight (LH) 
connector (4-pin).

• Is there continuity between the following 

connectors?
— Auto leveling control unit (main) connector 

(terminal K) and headlight (LH) connector 
(terminal 2A)

Yes

Go to next step.

No

Possible cause is an open circuit in headlight (LH). Replace 
headlight (LH). (See 

T–26 FRONT COMBINATION LIGHT 

REMOVAL/INSTALLATION

)

5

INSPECT HEADLIGHT (LH)

• Disconnect auto leveling control unit (main) 

connector (20-pin).

• Is there no continuity between the following 

connectors?
— Terminals K and E
— Terminals K and D
— Terminals K and L

Yes

Replace auto leveling control unit.
(See 

T–30 DISCHARGE HEADLIGHT CONTROL UNIT 

REMOVAL/INSTALLATION

)

No

Possible cause is an open circuit in headlight (LH). Replace 
headlight (LH). (See 

T–26 FRONT COMBINATION LIGHT 

REMOVAL/INSTALLATION

)

ON-BOARD DIAGNOSTIC [HEADLIGHT AUTO LEVELING SYSTEM] 

T–155

T

DTC B2616

A6E816467000W08

DTC B2616

Front auto leveling sensor signal system.

DETECTION 

CONDITION

Warning
• incorrect servicing of the auto leveling control unit could result in electrical shock because 

the unit is integrated with the discharge headlight control unit. Before servicing the auto 
leveling control unit, always refer to “Discharge headlight service warnings.” (See 

T–25 

DISCHARGE HEADLIGHT SERVICE WARNINGS

)

Output signal is not sent from the front auto leveling sensor.

POSSIBLE 

CAUS

• Front auto leveling sensor malfunction

• Open or short circuit in wiring harness between front auto leveling sensor and headlight (LH)

• Headlight (LH) malfunction

T–156

ON-BOARD DIAGNOSTIC [HEADLIGHT AUTO LEVELING SYSTEM] 

Diagnostic procedure

End Of Sie

STEP

INSPECTION

ACTION

1

INSPECT FRONT LEVELING SENSOR 

CONNECTION

• Check installation condition of front auto 

leveling sensor and fit of connector.

• Are installation condition and fit okay?

Yes

Go to next step.

No

After correcting fit, clear DTC and check DTC again.

• If DTC is displayed again, go to next step.

2

INSPECT WIRING HARNESS BETWEEN 

FRONT AUTO LEVELING SENSOR 
CONNECTOR AND HEADLIGHT (LH) 
CONNECTOR

• Disconnect front auto leveling sensor 

connector (6-pin) and headlight (LH) 
connector (4-pin).

• Is there continuity between the following 

connectors?
— Front auto leveling sensor connector 

(terminal B) and headlight (LH) connector 
(terminal 2C)

Yes

Go to next step.

No

Repair or replace wiring harness between front auto leveling 
sensor and headlight (LH).

3

INSPECT WIRING HARNESS BETWEEN 

FRONT AUTO LEVELING SENSOR 
CONNECTOR AND HEADLIGHT (LH) 
CONNECTOR

• Disconnect front auto leveling sensor 

connector (6-pin) and headlight (LH) 
connector (4-pin).

• Is there no continuity between the following 

connectors?
— Front auto leveling sensor connector 

(terminal B) and headlight (LH) connector 
(terminal 2B)

— Front auto leveling sensor connector 

(terminal B) and headlight (LH) connector 
(terminal 2A)

Yes

Go to next step.

No

Repair or replace wiring harness between front auto leveling 
sensor and headlight (LH).

4

INSPECT HEADLIGHT (LH)

• Disconnect auto leveling control unit (main) 

connector (20-pin) and headlight (LH) 
connector (4-pin).

• Is there continuity between the following 

connectors?
— Auto leveling control unit (main) connector 

(terminal H) and headlight (LH) connector 
(terminal 2C)

Yes

Go to next step.

No

Possible cause is an open circuit in headlight (LH). Replace 
headlight (LH). (See 

T–26 FRONT COMBINATION LIGHT 

REMOVAL/INSTALLATION

)

5

INSPECT HEADLIGHT (LH)

• Disconnect auto leveling control unit (main) 

connector (20-pin) and headlight (LH) 
connector (4-pin).

• Is there continuity between the following 

connectors?
— Auto leveling control unit (main) connector 

(terminal G) and headlight (LH) connector 
(terminal 2C)

— Auto leveling control unit (main) connector 

(terminal K) and headlight (LH) connector 
(terminal 2C)

— Auto leveling control unit (main) connector 

(terminal E) and headlight (LH) connector 
(terminal 2C)

Yes

Replace front auto leveling sensor.
(See 

T–32 FRONT AUTO LEVELING SENSOR REMOVAL/

INSTALLATION

)

No

Possible cause is an open circuit in headlight (LH). Replace 
headlight (LH). (See 

T–26 FRONT COMBINATION LIGHT 

REMOVAL/INSTALLATION

)