How To Change Battery In Subaru Key: Step-by-Step Replacement Guide
Replacing a dead Subaru key fob battery takes less than five minutes and requires only a flathead screwdriver and the correct coin cell lithium battery. By matching the precise Panasonic or Energizer CR2032 or CR1632 chemistry required for your specific model year, you can bypass dealership service fees and instantly restore complete remote keyless entry functionality.
Pre-Operation & Equipment Checklist
Successfully replacing your Subaru smart key or integrated ignition key fob battery relies on proper preparation, exact material selection, and adherence to clean handling protocols. Because modern vehicle access systems rely on secure radio frequency identification (RFID) and encrypted rolling codes, preventing physical damage to the internal printed circuit board (PCB) and maintaining circuit cleanliness are vital priorities.
- Essential Gear and Tools: A precision flathead screwdriver or a non-marring nylon spudger tool, a microfiber cleaning cloth, and the correct replacement lithium coin cell battery.
- Mandatory Prerequisite Knowledge: Identifying whether your specific fob uses a physical mechanical key extraction latch, a snap-fit housing design, or a secured retaining screw.
- Battery Specifications: Most modern push-to-start Subaru smart keys utilize a 3V CR2032 lithium coin cell, while older integrated mechanical blade remotes frequently rely on the slightly thinner CR1632 cell.
- Estimated Budget and Duration: Total financial investment ranges between four and ten dollars for a multi-pack of premium batteries, with a total operational time frame of three to five minutes.
Step-by-Step Subaru Key Fob Battery Replacement Workflow
Step 1: Extract the Hidden Mechanical Emergency Key
Locate the small sliding release tab or push-button located at the top head of your Subaru smart key fob housing. Slide this release mechanism firmly in the designated direction while simultaneously pulling the chrome or metal mechanical emergency key blade straight out of the base housing. Set the emergency key aside in a secure location, as its removal is mandatory to expose the internal chassis separation seams.
Warning: Never force the metal emergency key out without fully depressing the release latch, as this can permanently snap the internal plastic retaining clips inside the remote housing.
Step 2: Separate the Key Fob Plastic Shell Halves
Look inside the newly exposed slot where the mechanical key previously resided to locate the small, rectangular release notch or pry point molded directly into the plastic framing. Insert the tip of your flathead screwdriver or nylon pry tool into this slot and gently twist the tool like a door key. The plastic housing snap-fit seams will separate cleanly along the perimeter, splitting the remote into a front and rear shell half.
Step 3: Extract the Electronic Control Module
Carefully lift the internal rubberized keypad or the sealed electronic circuit board assembly out of the lower fob shell casing. If the circuit board remains seated snugly within the housing, use your non-marring tool to gently lift it from the edges without applying pressure to the delicate surface-mounted microswitches or the internal RFID transponder coil.
Pro-Tip: Handle the electronic module strictly by its outer edges to prevent transferring natural skin oils, moisture, or microscopic debris onto the gold contact pads and internal battery terminals.
Step 4: Remove the Depleted Lithium Battery
Examine the back of the electronic module to locate the circular battery compartment, which is typically secured beneath a plastic retainer clip or spring contact arm. Use your precision flathead screwdriver to gently slip underneath the edge of the spent coin cell battery, popping it free from its mounting cradle. Note the exact orientation of the battery before removal so the replacement sits identically.
Step 5: Install the New Replacement Battery
Take your new 3V lithium coin cell battery and wipe both sides clean with a dry microfiber cloth to remove manufacturing residues. Slide the new battery into the housing cradle with the positive side facing upward, ensuring standard text markings remain completely visible. Press down firmly on the center of the cell until you hear or feel it click securely underneath the metal or plastic retention clips.
Step 6: Reassemble and Test the Remote System
Align the front and rear plastic housing halves around the electronic control board and squeeze them together firmly with your fingers until all perimeter snap clips latch completely into place. Reinsert the metal emergency key blade back into its designated channel until the release latch clicks shut. Stand within range of your vehicle and test the lock, unlock, and panic functions to confirm proper electrical continuity and remote programming retention.
Subaru Forester Key Fob Battery
Subaru Key Battery and Model Compatibility Matrix
| Subaru Key Type | Model Years | Battery Size | Voltage | Common Tool Requirements |
|---|---|---|---|---|
| Push-to-Start Smart Key | 2015 – Present | CR2032 | 3V | Flathead Screwdriver / Pry Tool |
| Integrated Blade Remote | 2010 – 2019 | CR1632 | 3V | Precision Flathead Screwdriver |
| Standard Plastic Head Key | 2005 – 2014 | CR2016 | 3V | Phillips #0 Screwdriver |
| Advanced NFC Card Key | 2020 – Present | CR2430 | 3V | Non-Marring Spudger Tool |
Common Site Failures and Field Fixes
Symptom: The key fob red LED indicator light flashes when buttons are pressed, but the vehicle doors fail to lock or unlock.
- Root Cause: The new battery was installed upside down (negative side facing up), or the battery terminals have accumulated surface oxidation and grease.
- Actionable Fix: Disassemble the fob housing, remove the battery, clean the metal contact prongs with an isopropyl alcohol swab, and reinstall the cell with the positive (+) side facing outward.
Symptom: Total loss of remote functionality and complete failure of the dashboard proximity sensor after battery replacement.
- Root Cause: The vehicle's security system has dropped the rolling code synchronization due to an extended power loss during the battery swap, or the replacement battery voltage is below operational thresholds.
- Actionable Fix: Insert the mechanical emergency key into the driver-side door cylinder to unlock the vehicle, place the smart key fob directly against the push-to-start ignition button, and press the brake pedal while starting the engine to re-handshake the transponder.
Symptom: The plastic housing seams refuse to snap back together flush after installing the new battery.
- Root Cause: The internal electronic circuit board is misaligned within the molding channels, or the rubber gasket is bunched up along the edge.
- Actionable Fix: Separate the halves, reseat the PCB completely flat inside the alignment pins, verify the rubber seal sits flat in its track, and squeeze evenly around the outer perimeter.
Frequently Asked Questions
Do I need to reprogram my Subaru key fob after changing the battery?
No, changing the battery in a Subaru key fob does not erase the internal memory chip or the encrypted rolling codes stored on the circuit board. Your vehicle will immediately recognize the key once the fresh power source is installed, provided the battery is inserted correctly and makes solid contact with the terminals.
How do I know if my Subaru key needs a CR2032 or CR1632 battery?
The most reliable method to determine your exact battery size is to open the key fob housing and inspect the engraved text printed directly on the top surface of the old, depleted coin cell. Alternatively, you can consult your Subaru owner manual under the maintenance and keyless entry specifications section.
Why is my Subaru key fob still not working with a brand-new battery?
If a new battery fails to restore functionality, the issue usually stems from internal circuit board corrosion caused by moisture exposure, worn-out tactile microswitch buttons, or a de-synchronized transponder chip. Inspect the gold solder joints on the board under a magnifying glass for micro-fractures or water damage.
Can I damage my Subaru key fob by changing the battery myself?
While the plastic housing snaps together tightly, performing the replacement carefully with non-marring tools prevents cosmetic scratching and internal damage. Avoid using excessive leverage when prying the plastic shell apart to protect the delicate internal circuit traces from cracking.
Maintain peak convenience and security for your vehicle by performing routine preventative battery maintenance on all active and spare Subaru key fobs before complete power failure occurs.
