B1209 Code: Meaning, Causes, and Symptoms | OBD2 Codes

B1209 – Frontal Collision Detection

 

B1209 Possible Symptoms

 

Air Bag Warning Light ON

 

B1209 Possible Causes

 

Faulty Air Bag Diagnosis Sensor Unit (ACU),Air Bag Diagnosis Sensor Unit (ACU) harness is open or shorted,Air Bag Diagnosis Sensor Unit (ACU) circuit poor electrical connection

 

B1209 Description

 

Detects component damage resulting from a front collision, blinks or illuminates the air bag warning lamp to inform the driver. The air bag and seat belt pre-tensioners for driver and front seat passenger are operated by the decision of the Air Bag Diagnosis Sensor Unit (ACU) out signal transmitted because of the frontal collision. The Frontal Collision Detection consists of crash zone sensor, Air Bag Diagnosis Sensor Unit (ACU), air bags and seat belt pre-tensioners for driver and front passenger.