DTC B1638: Curtain Shield Airbag Sensor Initialization Error (LH) [06/2018 - 09/2022]: Description

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The side collision sensor LH circuit (bus 1) consists of the airbag ECU assembly, door side airbag sensor LH and side No. 2 airbag sensor assembly LH.

The door side airbag sensor LH and side No. 2 airbag sensor assembly LH detect impacts to the vehicle and send signals to the airbag ECU assembly to determine if the airbags and pretensioners should be deployed.

DTC B1638 is stored when a malfunction is detected in the side collision sensor LH circuit (bus 1).

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Test Mode / Check Mode
B1638	Curtain Shield Airbag Sensor Initialization Error (LH)	The airbag ECU assembly detects a line short, short to ground or B+, or an open in the side collision sensor LH circuit (bus 1). Side No. 2 airbag sensor assembly LH malfunction Airbag ECU assembly malfunction	Floor wire Front door wire LH Side No. 2 airbag sensor assembly LH Airbag ECU assembly	Comes on	Does not apply to test/check mode