DTC 21 [HEADLIGHT AUTO LEVELING SYSTEM]

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Description

• Rear auto leveling sensor signals

Detection Condition

• Rear auto leveling sensor signal voltage is less than 0.4 V, or 4.6 V or more

Possible Cause

• Open or short circuit between the rear auto leveling sensor and auto leveling control module

• Rear auto leveling sensor malfunction

• Auto leveling control module malfunction

System Wiring Diagram

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Diagnostic Procedure

Step

Inspection

Action

1

VERIFY REAR AUTO LEVELING SENSOR CONNECTOR CONNECTION

•  Is the rear auto leveling sensor connector connected securely?

Yes

Go to the next step.

No

Connect the connector securely and re-perform the DTC inspection.

•  If the malfunction recurs, go to the next step.

2

INSPECT WIRING HARNESS BETWEEN REAR AUTO LEVELING SENSOR AND AUTO LEVELING CONTROL MODULE

•  Turn the ignition switch to the LOCK position.

•  Disconnect the negative battery cable.

•  Disconnect the rear auto leveling sensor and auto leveling control module connectors.

•  Inspect the wiring harness between rear auto leveling sensor connector terminal B and auto leveling control module connector terminal N for the following:

―  Open circuit

―  Short to power supply

―  Short to body ground

•  Is the wiring harness normal?

Yes

Go to the next step.

No

Repair or replace the wiring harness between the rear auto leveling sensor and auto leveling control module.

After repair or replacement, perform the auto leveling system initial setting, and re-perform the DTC inspection.

•  If the malfunction recurs, go to the next step.

3

INSPECT REAR AUTO LEVELING SENSOR

•  Remove the rear auto leveling sensor.
(See REAR AUTO LEVELING SENSOR REMOVAL/INSTALLATION.)

•  Inspect the rear auto leveling sensor.
(See REAR AUTO LEVELING SENSOR INSPECTION.)

•  Is the rear auto leveling sensor normal?

Yes

Go to the next step.

No

Replace the rear auto leveling sensor.

(See REAR AUTO LEVELING SENSOR REMOVAL/INSTALLATION.)

After replacement, perform the auto leveling system initial setting, and re-perform the DTC inspection.

•  If the malfunction recurs, go to the next step.

4

PERFORM DTC INSPECTION

•  Install the rear auto leveling sensor.

•  Connect all the connectors.

•  Connect the negative battery cable.

•  Perform the auto leveling system initial setting.
(See AUTO LEVELING SYSTEM INITIALIZATION.)

•  Perform the headlight auto leveling system DTC inspection.
(See DTC INSPECTION [HEADLIGHT AUTO LEVELING SYSTEM].)

•  Is DTC 21 displayed?

Yes

Replace the auto leveling control module.

(See AUTO LEVELING CONTROL MODULE REMOVAL/INSTALLATION.)

No

DTC troubleshooting completed.

Step	Inspection		Action
1	VERIFY REAR AUTO LEVELING SENSOR CONNECTOR CONNECTION • Is the rear auto leveling sensor connector connected securely?	Yes	Go to the next step.
1		No	Connect the connector securely and re-perform the DTC inspection. • If the malfunction recurs, go to the next step.
2	INSPECT WIRING HARNESS BETWEEN REAR AUTO LEVELING SENSOR AND AUTO LEVELING CONTROL MODULE • Turn the ignition switch to the LOCK position. • Disconnect the negative battery cable. • Disconnect the rear auto leveling sensor and auto leveling control module connectors. • Inspect the wiring harness between rear auto leveling sensor connector terminal B and auto leveling control module connector terminal N for the following: ― Open circuit ― Short to power supply ― Short to body ground • Is the wiring harness normal?	Yes	Go to the next step.
2		No	Repair or replace the wiring harness between the rear auto leveling sensor and auto leveling control module. After repair or replacement, perform the auto leveling system initial setting, and re-perform the DTC inspection. • If the malfunction recurs, go to the next step.
3	INSPECT REAR AUTO LEVELING SENSOR • Remove the rear auto leveling sensor. (See REAR AUTO LEVELING SENSOR REMOVAL/INSTALLATION.) • Inspect the rear auto leveling sensor. (See REAR AUTO LEVELING SENSOR INSPECTION.) • Is the rear auto leveling sensor normal?	Yes	Go to the next step.
3		No	Replace the rear auto leveling sensor. (See REAR AUTO LEVELING SENSOR REMOVAL/INSTALLATION.) After replacement, perform the auto leveling system initial setting, and re-perform the DTC inspection. • If the malfunction recurs, go to the next step.
4	PERFORM DTC INSPECTION • Install the rear auto leveling sensor. • Connect all the connectors. • Connect the negative battery cable. • Perform the auto leveling system initial setting. (See AUTO LEVELING SYSTEM INITIALIZATION.) • Perform the headlight auto leveling system DTC inspection. (See DTC INSPECTION [HEADLIGHT AUTO LEVELING SYSTEM].) • Is DTC 21 displayed?	Yes	Replace the auto leveling control module. (See AUTO LEVELING CONTROL MODULE REMOVAL/INSTALLATION.)
4		No	DTC troubleshooting completed.