BMW Radio Problemsby Jim Hagerty
Car stereos made by BMW do tend to present their share or problems. While this is not unlike radios made by other manufacturers, the BMW brand (many models made by Alpine) has caused some audio shops to drop service on the lines altogether. From malfunctioning security codes to jammed CD players and mysterious error messages, replacing stock radios with aftermarket products is popular in some model year BMWs.
Security Code Problems
While many drivers experience an array of radio problems, a common issue BMW owners tend to wrestle with is the often constant need to reset the radio's security code, necessary for the unit to function. Generally, the only time a security code must be reset is when the car's battery dies or is replaced. However, some radios fail to read the original code without warning, prompting a change. When this occurs, drivers are often required to obtain a new code from BMW. This usually costs from $10 to $50, depending on the radio. Aside from obvious power culprits, security code problems are sometimes caused by other electrical problems within the vehicle's wiring system. Some audio techs can usually detect the problem and reset security codes fairly quickly, however, when the problem keeps occurring, swapping out the stock radio for a solid aftermarket model is sometimes warranted.
The dreaded CD jam error message is also common in some BMW radios. Some users find for various reasons, some obvious and some baffling, their CD players simply won't play discs and and error message displays a jam. This is common in some trunk-mounted disc changers. The problem is usually solved by locating the wire pin connectors, disconnecting them to drain power from the unit. When reconnected, the system sometimes will eject the jam and smooth operation continues. When it doesn't the unit must be removed and dismantled to remove the jam and replace the small belts and springs.
Volume Control Problems
In older BMW radio models, a common problem of erratic volume control often creates headaches for drivers. This issue is common on decks with manual volume knobs. When the user turns the volume up or down, sound will get suddenly and extremely loud, or muffled, as if turned off. To resolve the problem, a spray commonly called a control cleaner or contact solution is sprayed on the volume contact, removing dust and dirt, allowing the points to properly record volume levels.
Many BMW models have sophisticated speaker placement. Speakers are located in the dash, doors, side panels and back windows. After a while, drivers experience pops and cracks on some or all speakers when the radio is playing. A whistle is sometimes heard when the accelerator is pressed. There are several causes and fixes for speaker malfunction. First, the obvious is a blown speaker, which is simply replaced. Ground and power wires sometimes get jarred loose or fall from their connectors, causing intermittent disruptions in sound quality. Speaker wires sometimes lose their soldering points. The solution usually involves securing the wiring harnesses, making sure power wires are secure and the system is properly grounded to the chassis. Speaker wires are also re-soldered.
Especially in later models, BMW radios are mostly digitally-operated. They are also capable of powering other aftermarket devices such as MP3 players, mobile phones and GPS systems. This process is usually done by paring the electrical system to run secondary devices. This sometimes causes the radio's digital signals to get crossed, creating incorrect error messages and interrupting lights on the stereo unit. When this occurs, the installation of additional devices is checked thoroughly for incorrect electrical connections. Some aftermarket devices must be disconnected for the radio to function properly.