Mazda 6. Manual — part 351

T–32 FRONT AUTO LEVELING SENSOR REMOVAL/

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

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.

Go to step 4.

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

INSTALLATION

T–32 REAR AUTO LEVELING SENSOR REMOVAL/

After replacement, clear DTC and check DTC again.

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

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

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

INSTALLATION

After replacement, clear DTC and check DTC again.

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

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

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.

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

T–30 DISCHARGE HEADLIGHT CONTROL UNIT

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

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

DISCHARGE HEADLIGHT SERVICE WARNINGS

ON-BOARD DIAGNOSTIC [HEADLIGHT AUTO LEVELING SYSTEM]

T–155

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

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

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.

After correcting fit, clear DTC and check DTC again.

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

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.

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

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.

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

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.

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

T–32 FRONT AUTO LEVELING SENSOR REMOVAL/

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

INSTALLATION

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