Subaru Forester Remote Start Not Working: Causes, Fixes, and What to Check First

If your Subaru Forester remote start is not working, the cause is often a simple issue with the key fob, vehicle settings, or a safety interlock.

This guide walks through the most common reasons the system refuses to start and the fastest checks to narrow down the problem.

How Subaru Forester remote start works

The Subaru Forester remote start system depends on the key fob, vehicle security module, starter control logic, and several safety checks.

If any required condition is not met, the system will cancel the start request instead of cranking the engine.

On most Forester models, remote start will only work when the vehicle is in a safe state and the system can confirm authorization.

That means the issue may be with the fob signal, a low battery, an open hood, a check engine light, or a door that is not fully latched.

Most common reasons Subaru Forester remote start is not working

1. The key fob battery is weak

A weak key fob battery is one of the most common causes of Subaru Forester remote start not working.

The fob may still lock and unlock doors at short range, but remote start often needs a stronger signal than basic lock functions.

If the fob battery is low, replace it with the correct coin-cell battery specified for your model year.

After replacement, test the remote start again from a normal distance.

2. The vehicle battery is low

Even if the key fob works, the Forester may reject remote start when the 12-volt battery is weak.

Subaru remote start systems monitor vehicle voltage because a low battery can prevent reliable starting or create a no-start condition.

Watch for slow cranking, dim interior lights, or recent jump-starts.

If the vehicle battery is old or repeatedly discharged, have it tested with a load tester at a dealer or auto parts store.

3. A door, hood, or liftgate is open

Safety switches can block remote start if the system detects an open door, hood, or rear gate.

Even a partially latched hood can trigger a no-start response.

Check every door, the rear gate, and especially the hood.

Close them firmly and make sure the hood latch clicks fully into place.

4. The check engine light is on

Many Subaru Forester models disable remote start when the check engine light is illuminated.

This is a protective feature because engine or emissions faults can make remote operation unreliable or unsafe.

If the check engine light is on, scan the vehicle for diagnostic trouble codes with an OBD2 scanner.

Fix the underlying issue first, then retest remote start after clearing codes if appropriate.

5. The car is not in Park

Remote start will not engage unless the transmission is confirmed in Park.

If the shifter was recently moved, the vehicle rolled slightly, or the system does not recognize Park correctly, the start request may fail.

Shift into Park, turn the car off normally, and try the sequence again.

If the indicator is inconsistent, have the shift selector or range sensor inspected.

6. The alarm or security system was triggered

If the alarm has been activated or the vehicle recently experienced a security event, the remote start feature may be temporarily disabled.

A failed unlock attempt, a break-in alert, or some aftermarket security systems can interfere with Subaru authorization logic.

Lock and unlock the vehicle using the fob, then attempt remote start again.

If an aftermarket alarm or remote start module is installed, verify that it is compatible with Subaru systems.

Quick checks to perform before calling a dealer

• Replace the key fob battery if it is older than a year or has never been changed.
• Confirm the vehicle battery is healthy and fully charged.
• Make sure all doors, the hood, and the rear gate are fully closed.
• Check whether the check engine light or another warning light is on.
• Verify the transmission is in Park.
• Try the remote start from the recommended distance and avoid interference from metal objects or other electronic devices.

How to test the remote start system correctly

To avoid false symptoms, test the system under normal conditions.

Stand within the recommended range, press the lock button first if your system requires it, and then use the remote start sequence specified in your owner’s manual or connected app.

If the vehicle starts once and then stops immediately, pay attention to any dashboard messages.

Subaru systems often provide clues such as hood open, key not detected, or engine fault warnings that point directly to the cause.

Subaru app and connected services issues

If you use Subaru Connected Services or the MySubaru app, the problem may be in the account, subscription, or cellular connection rather than the vehicle itself.

Remote start commands sent through the app depend on an active service plan, proper login credentials, and network connectivity.

Check for these app-related issues:

• Expired or inactive remote services subscription
• Logged out account or incorrect password
• Weak mobile data or no signal on the vehicle side
• App update required on your phone
• Account not properly linked to the VIN

If the app fails but the key fob works, the issue is likely software or account-related rather than a mechanical fault.

Aftermarket accessories that can interfere with remote start

Aftermarket alarms, remote starters, dash cams with hardwire kits, GPS trackers, and battery monitors can sometimes interfere with Subaru electrical systems.

Poorly installed accessories may create voltage drops or false security signals that prevent remote start from working.

If the problem started after an accessory installation, remove the accessory from the equation or have the wiring inspected by an experienced automotive electrician.

What Subaru Forester owners can do about repeated failures

If Subaru Forester remote start is not working repeatedly, a more systematic diagnosis helps.

Document when the failure occurs, whether it happens only in cold weather, and whether the key fob or app is affected.

Bring this information to a Subaru dealer or qualified technician:

• Model year and trim level
• Whether the system uses the fob, app, or both
• Any warning lights on the dash
• Recent battery replacement, jump-start, or repair history
• Exact behavior when the start request is made

When to visit a Subaru dealer

A dealer visit makes sense if the key fob battery, vehicle battery, and obvious safety checks all look normal but remote start still fails.

Subaru technicians can scan body control modules, remote entry logs, and fault codes that generic scans may miss.

Dealer diagnostics are especially useful when the issue is intermittent, because stored data can show whether the problem is caused by voltage, communication errors, or a specific sensor input.

Model-year and software factors

Some Forester years use different remote start methods, including factory key fob start, subscription-based app control, or dealer-installed accessories.

That means the exact troubleshooting steps can vary by trim and model year.

Software updates, telematics service changes, and body control module calibrations can also affect behavior.

If your vehicle recently had a battery replacement, ECU update, or infotainment service, mention that during diagnosis.

Practical fix order for Subaru Forester remote start not working

1. Replace the key fob battery.
2. Check the vehicle battery and charging system.
3. Confirm all doors, hood, and liftgate are closed.
4. Verify the transmission is in Park.
5. Look for warning lights, especially the check engine light.
6. Test both the key fob and app if your Forester supports both methods.
7. Inspect aftermarket accessories for interference.
8. Schedule Subaru diagnostics if the problem continues.

Working through these checks in order eliminates the most common causes quickly and helps pinpoint whether the issue is simple, electrical, or module-related.