B2404 Code: Meaning, Causes, and Symptoms | OBD2 Codes
B2404 – Audio Steering Wheel Switch Circuit Fault
B2404 Possible Symptoms
Engine Light ON (or Service Engine Soon Warning Light)
B2404 Possible Causes
Faulty Audio Steering Wheel Switch,Audio Steering Wheel Switch harness is open or shorted,Audio Steering Wheel Switch circuit poor electrical connection
Two different steering wheel switch configurations are available, depending on whether the vehicle is equipped with the SYNC system. On vehicles without the SYNC system, all of the steering wheel control switches are wired to the Audio Control Module (ACM). The steering wheel controls are: VOL+, VOL-, SEEK+, SEEK-, and MEDIA. The SEEK+ and SEEK- switches are represented by arrows. For vehicles equipped with the SYNC system, the steering wheel controls are: VOL+, VOL-, SEEK+, SEEK-, MEDIA, VOICE, PHONE, and OK. The SEEK+ and SEEK- switches are represented by arrows, the VOICE button is represented by an icon of someone speaking, and the PHONE button is represented by an icon of a phone with an up-and-down arrow. The VOICE, PHONE, and OK switches are wired to the accessory protocol interface module (APIM), while the remaining switches are wired to the ACM. For all switches, a reference voltage is sent from the appropriate module to the steering wheel controls. When a switch is pressed, the voltage is routed through a specific resistor value for each function. The module provides the ground for the reference voltage. The module uses this reference voltage to determine which control input function has been selected.