Why is my Subaru Forester not turning on?

[Zion]

Your Subaru Forester won't start primarily due to a dead battery, a faulty starter, or a security system/immobilizer issue. Less common but notable causes include a failed Torque Converter Valve (TCV) in newer models and fuel system problems. Immediate actions include checking battery voltage, attempting a jump-start, trying to start in Neutral, and verifying your key fob.

Battery problems are the leading culprit, responsible for an estimated 60-70% of no-start incidents. Even if dashboard lights illuminate, the battery may lack the necessary Cold Cranking Amps (CCA) to engage the starter. Models like the 2018 Forester are documented in owner forums and technical service bulletins for higher-than-average battery drain issues. Check for corrosion on terminals and ensure cables are tight. A healthy battery should show at least 12.4 to 12.6 volts when the car is off. Voltage dropping below 10V during a crank attempt indicates a failed battery.

Starter motor failure is another frequent cause. Symptoms include a single loud click or repetitive rapid clicking when turning the key, often with dimming lights. The starter is located on the passenger side of the engine. Sometimes, a failing starter can be temporarily resolved by tapping it with a tool, but this is a clear sign it needs replacement.

Security/Immobilizer system issues can prevent the engine from cranking. If a flashing car/key symbol appears on the dash, the system does not recognize your key. Try using the spare physical key, or press the lock/unlock buttons on your fob to reset the signal. A dead fob battery can also cause this; many Subarus have a procedure to start by holding the fob against the start button.

Torque Converter Valve (TCV) failure is a known issue in some newer Subarus. A faulty TCV can cause a "no-crank" condition even with full dash lights. This problem is often intermittent and may be covered under a warranty extension. Diagnosis typically requires professional scan tools.

Other causes include a failing fuel pump (engine cranks but doesn't start), a faulty crankshaft position sensor, or a blocked fuel filter. In very cold weather, some owners report needing two full key cycles (ON to OFF) before a successful start.

Symptom	Most Likely Cause	Immediate Action
Clicking sound, no crank	Weak/dead battery, loose cables, bad starter	Jump-start, check/tighten battery connections
Silence, dash lights on	Bad starter, security lockout, faulty TCV	Try spare key, start in Neutral, seek diagnosis
Cranks but won't start	Fuel pump, ignition, or sensor issue	Listen for fuel pump hum at key "ON"

If basic troubleshooting fails, professional diagnosis is needed. A mechanic will check for error codes, verify fuel pressure, and perform a starter circuit test to pinpoint the exact failure point.

[LaAriel]

Just went through this last month with my 2019 Forester. Total silence when I turned the key—just the dash lights. I felt that panic. The roadside guy jumped it, and it started right up. Turns out, the original battery was just done after four years. He said Subarus are tough on batteries with all their electronics always running in the background. Got a new one with higher CCA, and it’s been perfect since. My lesson? Don’t wait for the battery to die completely. If it’s over three years old and you see any slow crank, just replace it preemptively. Saved me a huge hassle.

[ZaneAnn]

As a technician, I see a pattern. For a no-crank with lights, we first rule out the simple stuff: battery voltage and terminal connection. A load test tells us more than just voltage. Next, we listen for the starter solenoid click. If we hear it but no crank, it’s often the starter itself. No click leads us to check the ignition switch, neutral safety switch, or that pesky TCV valve.

The TCV issue is specific. The car thinks the transmission isn’t in Park or Neutral, so it won’t allow a crank. It doesn’t throw a simple code for this. We perform a functional test of the valve body. For a crank/no-start, our flow is spark, fuel, then compression. A quick check for fuel pump prime is easy—you should hear a brief hum from the rear when you first turn the key to ON. No hum points to the pump, its relay, or the control circuit.

[DylanRose]

Hey folks, here’s a quick checklist from my own driveway experience. Go step-by-step before you call a tow.

1. Key Fob: Is the security light blinking? Press unlock on the fob. Try starting with the fob physically touching the start button.
2. Battery Terminals: Pop the hood. Are the terminals clean and tight? Wiggle them. Corrosion looks like white or blue crust.
3. Shifter: Jiggle it in Park. Or, step on the brake and try starting in Neutral.
4. Listen: When you turn the key to “ON” (not start), do you hear a faint whir from the back? That’s the fuel pump. No sound might be your issue.
5. Lights: Turn on the headlights and try to start. If they go dramatically dim, your battery is flat.

If all this gets you nothing, it’s likely beyond a simple fix and needs a pro’s scan tool.

[DeCharlie]

Let’s talk about the less obvious one: the Torque Converter Valve. My 2020 Forester left me stranded twice with all lights on but no crank. It was random and infuriating. The dealer finally identified it as the TCV in the valve body. They explained it as a communication fault within the transmission that tells the computer the car isn’t safe to start. It was covered under a warranty extension.

The repair involved replacing the entire valve body, which is a significant job. The symptom is very distinct: everything electrical works perfectly, but the starter doesn’t engage at all—no click, nothing. It feels like a giant, expensive safety feature locking you out. If you’re out of warranty, this is a costly fix. Before assuming the worst, absolutely rule out the battery and key fob first, as they mimic the same symptom. But if your Forester is 2019 or newer and has this specific no-crank with full power, mention the TCV to your mechanic. It’s a known fault.