Changing the battery in your Lexus ES350 key fob is a straightforward procedure that saves you time and money compared to a dealership visit. This simple task ensures your remote entry system, panic button, and trunk release continue to function without interruption. Most owners can complete the process in under five minutes with the right tools.
Identifying Your Key Fob Model
Before beginning the battery replacement, verify you have the correct component for your specific model year. The design for the ES350 remained consistent for many generations, but it is always good practice to confirm. Look for the model number printed on the back of the fob, which is typically a small plastic case.
The standard unit for the Lexus ES350 utilizes a CR2032 3V lithium coin cell battery. This is a widely available standard battery found in most pharmacy or electronics stores. Ensure the voltage matches exactly; using a lower voltage battery will result in weak signals, while a higher voltage can damage the internal circuitry.
Required Tools and Preparation
One CR2032 3V lithium battery
A small flathead screwdriver or a coin
A clean, flat working surface
Soft cloth (optional, to prevent scratches)
Gather these items before starting to avoid searching for tools mid-process. Choose a well-lit area to work in so you can clearly see the internal components. Placing a soft cloth on your desk will protect the key fob from scratches during the procedure.
Step-by-Step Disassembly
Accessing the Internal Housing
The key fob is secured with a hidden screw located beneath the rubber flip cover. Use your fingernail or a small coin to carefully pry off the flip cover at the seam. Once removed, you will see a small Phillips head or flathead screw that keeps the fob closed.
Using the appropriate screwdriver, loosen the screw slightly. You do not need to remove it completely; simply loosening it allows the two halves of the fob to separate more easily. Carefully pull the two sides apart, noting how the internal components are arranged for reassembly.
Battery Removal and Inspection
Locate the battery, which is usually held in place by a small plastic bracket or is simply seated in a cavity. Note the orientation of the old battery; there is typically a plus (+) side facing up. Gently lift the old battery out using your fingers or the edge of a screwdriver.
Before installing the new battery, take a moment to inspect the metal contacts. Wipe away any dust or corrosion with a dry cloth to ensure a solid electrical connection. This maintenance step helps extend the life of the new battery and prevents intermittent functionality.
Installing the New Battery
Take your new CR2032 battery and hold it with the positive side (+) facing up. Align the battery with the slot and gently press it into place until it sits flush. You should hear or feel a slight click as it locks into position.
If your fob has a plastic bracket, reposition it over the battery to hold it securely. Ensure the battery is not loose, as movement can cause connection issues. Double-check the polarity to match the previous installation; reversing the contacts can prevent the fob from working.
Reassembly and Testing
Carefully align the two halves of the key fob, making sure the internal circuit board and buttons are properly seated. Hand-tighten the screw back into place or press the flip cover back onto the unit until it clicks. Avoid overtightening the screw, as this can crack the plastic housing.
