Parts for your 2016 Subaru Impreza-Alternator

2016 Subaru Impreza Alternator — what it does and how to look after it

For the 2016 Subaru Impreza, an alternator is absolutely fitted and relevant. Technical references including the Subaru Factory Service Manual for the 2012–2016 Impreza (Electrical – Charging System) and Subaru’s parts catalogue for the FB20 engine list a belt‑driven, ECU‑controlled alternator as standard equipment. It’s a Denso‑type unit designed to keep the 12‑volt system charged while the engine’s running.

In day‑to‑day driving, the alternator turns mechanical energy from the engine into electrical energy to maintain battery charge and power everything from headlights and fans to the ECU and safety systems. Without a healthy alternator, the battery quickly discharges and the car can stall or fail to restart.

Servicing the alternator on a 2016 Impreza is mostly about smart checks rather than constant replacement. At each service, it’s wise to inspect the serpentine belt for cracks or glazing and confirm correct tension, check battery terminals and grounds for corrosion, and listen for bearing noise from the alternator pulley. A quick multimeter test at the battery with the engine running should show roughly 13.8–14.6 volts, significantly less (or more) suggests a charging issue that needs attention.

Replacement is straightforward for a trained tech: disconnect the negative battery terminal, relieve belt tension, unplug the connector and main charge cable, and remove the mounting bolts. Refitting is the reverse, followed by a voltage test and a scan for any stored charging‑system codes. Many workshops can test and rebuild these units, but if the regulator or windings are tired, a quality remanufactured or new unit is usually the most reliable fix.

• Common warning signs: battery light glowing, dimming lights at idle, whining or grinding from the alternator area, frequent flat battery, or fluctuating dash voltage.
• Simple driveway checks: inspect the belt, clean and tighten battery terminals, and measure charging voltage after a cold start and with accessories on.

Owners who keep up with these basics generally get long life from the factory alternator. If the alternator is original and the car’s clocking up higher kilometres, pre‑emptive testing during scheduled servicing can save a roadside headache later.

Popular questions about 2016 Subaru Impreza alternators

How long should the alternator last?
Many see well over 150,000 km, but life varies with driving habits, heat, and accessory load. Regular belt and battery upkeep helps stretch its lifespan.

What voltage should I see at the battery when the engine’s running?
Expect around 13.8–14.6 V with a healthy alternator. If you’re seeing low 13s or anything above mid‑14s consistently, it’s time for a proper test.

Can I drive if the battery light comes on?
You’ll be running on stored battery energy only, so range is limited and a stall is possible. It’s best to head straight to a workshop rather than risk getting stranded.