B125A Code: Meaning, Causes, and Symptoms | OBD2 Codes

B125A – Antenna Signal Circuit

 

B125A Possible Symptoms

 

Engine Light ON (or Service Engine Soon Warning Light)

 

B125A Possible Causes

 

Faulty Radio Antenna Base (Cellular Phone, Navigation and Digital Radio Antenna),Radio Antenna Base harness is open or shorted,Radio Antenna Base circuit poor electrical connection,Faulty Radio Unit

 

B125A Description

 

The AM/FM antenna is part of the multi-band antenna is located on the roof of the vehicle. The radio provides battery voltage to the AM/FM amplifier in the antenna base using the center conductor of the antenna coaxial cable. When a 12 V signal is seen by the amplifier, both AM and FM signals are amplified. The OBDII code sets when the radio detects an open or short to ground in the antenna signal circuit center conductor.