What does it mean?
B1405 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Front Right Audio Speaker Output Circuit Low .
Symptoms
- No sound or weak, distorted sound from the front right speaker
- The amplifier may mute that channel or shut the whole system down to protect itself
- Sound cuts in and out as the passenger door is opened and closed if the fault is in the hinge boot
- Crackling from the front right before the channel goes quiet
- Fader and balance test confirms the front right corner is the problem
Likely causes
- Front right speaker voice coil shorted or partly shorted
- Speaker wire shorted to ground where the passenger door harness passes through the hinge boot
- Aftermarket speaker with an impedance lower than the factory amplifier is designed to drive
- Wiring pinched behind the passenger door trim after speaker or window regulator work
- Corroded speaker terminals after water entered the passenger door
- On systems where the right channel also feeds a dash tweeter, a fault in that second driver or its crossover
- Amplifier output stage failure
How to fix it
- Fade fully to the front right and confirm which driver is affected, checking the dash tweeter as well on systems that have one
- Disconnect the speaker and measure its voice coil resistance; a value near zero means a shorted speaker
- With the speaker disconnected, check both speaker wires from the amplifier plug for a short to ground and to each other
- Flex the passenger door hinge boot harness while measuring, since that section takes all the door movement
- Remove any aftermarket speaker or adapter whose impedance does not match the factory system
- Repair the shorted wire and replace the speaker if its coil is shorted
- Replace or repair the amplifier only after the speaker and its wiring have been proven good