Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
B125A 02 Antenna Signal Circuit Short to Ground
B125A 04 Antenna Signal Circuit Open Circuit
Poor AM and FM radio reception may be due to multiple influences, some of which may not be vehicle related. Areas which have high RF traffic or block the signal path may cause a degradation in radio reception. Radio reception may also be influenced by items within the vehicle, but not part of the radio system. Such examples are aftermarket electrical accessories or other items which may generate noise in the vehicle electrical system. Aftermarket window tinting, especially when there is a metallic in the film, may reduce radio reception.
AM reception is highly dependent on the antenna amplifier receiving battery voltage from the radio and being properly grounded. The antenna base has a built in antenna amplifier that boosts both AM and FM reception. When the antenna amplifier does not receive power, AM stations may not be received and FM reception will be limited. If the antenna base is not properly grounded, excessive interference in the signal may occur or reception may be limited.
The cost to diagnose the B125A code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
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.
Need more information on how to fix the B125A code? Get Access to Factory Service Manuals
Get the B125A code diagnosed by a professional: Find a repair shop in your area