Are you experiencing issues with your 2001 BMW X5 key fob? Many owners of the E53 generation X5, especially those with the diamond-shaped key, find themselves facing a common problem: the key fob remote functions, like locking and unlocking, stop working. However, the key might still start the car without any issues. This often leads owners to wonder if there’s a simple fix, particularly concerning the key fob battery.
It’s a known characteristic of these BMW diamond keys, introduced around the year 2000 for models like the E53 X5, E46 3 Series, and E39 5 Series, that they contain a rechargeable battery. This battery is designed to power the remote keyless entry system, and it recharges inductively when the key is in the ignition. Over time, like any rechargeable battery, the capacity diminishes with charge cycles. According to a comment from someone claiming to be a former BMW engineer, these batteries typically last 10-15 years under normal usage.
If your 2001 BMW X5 key fob is no longer reliably locking or unlocking your doors remotely, but the key still starts the car, a failing rechargeable battery is a prime suspect. One user on a BMW forum experienced this exact scenario. They had modified diamond keys into fobs and noticed the remote functions becoming inconsistent. They even tried manually charging the fobs by holding them near the ignition cylinder for extended periods, a method sometimes used to revive a weak battery. While this might have offered temporary relief in the past, eventually, the batteries in their fobs seemed to give out completely.
The good news is that replacing the battery in these diamond key fobs is often a viable DIY solution. A popular YouTube tutorial demonstrates the process of opening the key fob and replacing the internal battery. The correct replacement battery is often cited as the Panasonic VL2020, but it’s crucial to ensure it has the correct connection geometry, specifically with 90-degree pin spacing, to match the original.
While some might consider using a non-rechargeable battery, the expert comment advises against it. The original design incorporates a rechargeable vanadium pentoxide battery that’s meant to be charged through electromagnetic induction in the ignition. Replacing it with a primary, non-rechargeable cell might lead to unforeseen issues and is not the intended design. Full recharge from a completely flat battery can take around 30 hours of ignition time in position 2 or 3, and even a short 1-hour charge can provide approximately 15 lock/unlock cycles, depending on the battery’s age and condition.
If you’re facing issues with your 2001 BMW X5 key fob remote functions, don’t immediately assume you need a costly new key. Exploring a DIY battery replacement for your diamond key fob could be a cost-effective and satisfying solution to restore your key’s remote capabilities. Just be sure to source the correct Panasonic VL2020 battery with the appropriate pin configuration and proceed carefully with the disassembly and reassembly process as shown in online guides.
