DTC B2390


DTC B2390	Communication system between auto leveling control unit (main) and auto leveling control unit (sub).
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 DISCHARGE HEADLIGHT SERVICE WARNINGS) Communication between auto leveling control unit (main) and auto leveling control unit (sub) is not performed.
POSSIBLE CAUSE	• Auto leveling control unit (main) malfunction • Open or short circuit in wiring harness between auto leveling control unit (main) and auto leveling control unit (sub)


STEP	INSPECTION		ACTION
1	INSPECT CONNECTOR CONNECTION • Check fit of auto leveling control units and headlight connectors on both sides (auto leveling control unit (main) and (sub)). • Are installation condition and fit okay?	Yes	Go to next step.
1		No	After correcting fit, clear DTC and check DTC again. • If DTC is displayed again, go to next step.
2	INSPECT HEADLIGHT (LH) AND HEADLIGHT (RH) • Disconnect auto leveling control unit (main) connector (20-pin) and headlight (LH) connector (12-pin) and auto leveling control unit (sub) connector (20-pin) and headlight (RH) connector (12-pin). • Is there continuity between the following connectors? - Auto leveling control unit (main) connector (terminal I) and headlight (LH) connector (terminal 1F) - Auto leveling control unit (sub) connector (terminal P) and headlight (RH) connector (terminal 1F)	Yes	Go to next step.
2		No	Possible cause is an open circuit in headlight. Replace headlight (LH) or headlight (RH). (See FRONT COMBINATION LIGHT REMOVAL/INSTALLATION)
3	INSPECT WIRING HARNESS BETWEEN HEADLIGHT (LH) CONNECTOR AND HEADLIGHT (RH) CONNECTOR • Disconnect headlight (LH) connector (12-pin) and headlight (RH) connector (12-pin). • Is there continuity between the following connectors? - Headlight (LH) connector (terminal 1F) and headlight (RH) connector (terminal 1F)	Yes	Repair auto leveling control unit (main). (See DISCHARGE HEADLIGHT CONTROL UNIT REMOVAL/INSTALLATION)
3		No	Repair or replace wiring harness between headlight (LH) and headlight (RH).