Subaru Ascent 2018-2026 Owner's Manual: Replacing key battery

The battery inside the access key fob or transmitter of your Subaru Ascent may gradually lose charge over time. This can become noticeable under several conditions.

• The keyless access system of your Subaru Ascent begins to respond inconsistently or with delays.
• The effective operating range of the remote keyless entry becomes shorter or unreliable.
• The transmitter fails to function properly even when used within normal operating distance.

When any of these symptoms occur, it is recommended to replace the battery with a new one to restore full functionality of your Subaru Ascent key system.

Safety precautions

CAUTION

• Prevent dust, oil, or moisture from entering the access key fob of your Subaru Ascent during battery replacement, as contamination may damage internal components.
• Discharge any static electricity from your body before handling the battery or internal parts to avoid electronic damage.
• Avoid touching or damaging the internal circuit board of the transmitter while replacing the battery.
• Keep batteries and small components away from children, as they pose a serious choking hazard if swallowed.
• Incorrect battery installation may cause an explosion.

  Always replace the battery with the same or an equivalent type recommended for your Subaru Ascent.

• Do not expose batteries to excessive heat sources such as direct sunlight, fire, or high temperatures.

NOTE

• Use only the battery type specified by the manufacturer for your Subaru Ascent to ensure reliable performance.
• Dispose of used batteries in accordance with local environmental regulations.
• Install the battery in the correct orientation to prevent leakage and ensure proper electrical contact.

  Avoid bending battery terminals during installation.

  Improper installation may lead to malfunction.

• If you are uncertain about the procedure, it is advisable to have the battery replaced by a SUBARU dealer.
• Always install a new battery rather than reusing an old one.
• After replacement, verify that all key functions operate correctly with your Subaru Ascent.

Replacing battery of access key fob

CAUTION

When removing or reinstalling the access key fob cover, ensure that all plastic components remain properly aligned and securely fitted.

Battery: Button battery CR2032 or equivalent

1. Release button
2. Emergency key

1. Remove the emergency key from the Subaru Ascent key fob.

2. Wrap a flat-head screwdriver with a soft material such as vinyl tape or cloth, then carefully insert it into the gap to open the key fob cover.

3. Remove the old battery using the protected screwdriver, taking care not to damage internal components.

4. Insert a new battery into the Subaru Ascent key fob with the positive (+) side facing upward, as illustrated.

5. Reattach the key fob cover by aligning and pressing together the locking tabs until securely closed.

Replacing battery of transmitter

CAUTION

Before beginning, ensure any static electricity is discharged to avoid damaging sensitive electronics.

Battery: Button battery CR2025 or equivalent

1. Open the key head using a flat-head screwdriver.

2. Remove the transmitter case from the key head assembly.

3. Carefully open the transmitter case by releasing its retaining hooks.

1. Negative (−) side facing up

4. Replace the battery with a new CR2025 unit, ensuring the negative (−) side faces upward as shown.

5. Reassemble the transmitter case by securely snapping the hooks back into place.

6. Insert the transmitter back into the key head.

7. Reattach the remaining part of the key housing.

After the battery is replaced, the transmitter must be synchronized with the remote keyless entry system of your Subaru Ascent. Press either the " " or " " button six times to complete synchronization.

Proper maintenance of your Subaru Ascent key battery ensures reliable remote access, secure locking functions, and consistent performance in everyday use.