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2017 Impreza Battery Keeps Dying: Diagnose & Fix Drain

By ClearTheCode · Published 2026-05-31 · ~7 min read

Is your 2017 Impreza battery keeps dying unexpectedly? Learn common causes, diagnostic steps, and effective fixes to resolve excessive battery drain and restore reliable starting.

At a glance

Difficulty
6/10 — Easy to moderate
Est. repair cost
$80 – $900 (parts + typical shop labor)
OEM tooling
Standard OBD-II scanner and hand tools
Common symptoms
  • Battery light on: While often indicating a charging system problem (alternator)
  • it can also illuminate if the battery v
  • Corrosion on battery terminals: White or blue powdery substance around the terminals can hinder charging and discharge.
  • Clicking sound when trying to start: This often indicates insufficient power to engage the starter motor.
  • Faint smell of sulfur: A sign of an overcharging or failing battery
  • though less common with parasitic drains.

There's nothing quite as frustrating as heading out to your 2017 Subaru Impreza, turning the key, and being met with silence or a sluggish groan. If your 2017 Impreza battery keeps dying, leaving you stranded or needing frequent jump starts, you're experiencing a common issue that can stem from various sources, ranging from a simple oversight to a more complex electrical problem. This guide will walk you through understanding why your battery might be draining excessively, how to diagnose the root cause, and the steps you can take to fix it, ensuring your Impreza starts reliably every time.

What drivers notice on this 2017 Subaru Impreza

Owners of the 2017 Subaru Impreza often report a range of symptoms when their battery is experiencing excessive drain. These can escalate from minor annoyances to complete vehicle immobilization.

  • Repeated dead battery: The most obvious sign, requiring jump starts or a battery charger frequently.
  • Slow or weak cranking: The engine struggles to turn over when starting, especially after the vehicle has been off for a few hours or overnight.
  • Dimming lights: Headlights, interior lights, or dashboard lights appear dimmer than usual.
  • Electronic glitches: Malfunctioning radio, infotainment system, power windows, or other electrical accessories.
  • Warning lights: The battery light or other warning indicators may illuminate on the dashboard, though not always directly related to a parasitic draw.
  • No-start condition: The vehicle is completely unresponsive when attempting to start, with no lights or accessories working.

At a glance: difficulty, repair cost, and diagnostic workflow

  • Difficulty Rating: 6/10 — Easy to moderate
  • Common Symptoms: Battery light on: While often indicating a charging system problem (alternator), it can also illuminate if the battery v; Corrosion on battery terminals: White or blue powdery substance around the terminals can hinder charging and discharge.; Clicking sound when trying to start: This often indicates insufficient power to engage the starter motor.; Faint smell of sulfur: A sign of an overcharging or failing battery, though less common with parasitic drains.
  • Estimated Repair Cost: $80–$900 (parts + typical shop labor)
  • OEM Tooling Required: Standard OBD-II scanner and hand tools

Diagnostic workflow:

  1. Confirm the symptom on your vehicle.
  2. Scan for stored or pending codes with an OBD-II tool.
  3. Inspect the most common causes in this guide (visual checks first).
  4. Run verification tests before replacing parts.
  5. Repair, clear codes, and verify on a test drive.

Symptoms and warning signs

Beyond the primary symptom of a dead battery, pay attention to these subtle clues that might indicate an underlying electrical issue in your 2017 Impreza:

  • Battery light on: While often indicating a charging system problem (alternator), it can also illuminate if the battery voltage drops too low.
  • Corrosion on battery terminals: White or blue powdery substance around the terminals can hinder charging and discharge.
  • Clicking sound when trying to start: This often indicates insufficient power to engage the starter motor.
  • Faint smell of sulfur: A sign of an overcharging or failing battery, though less common with parasitic drains.
  • Unusual warmth from electrical components: A component that's drawing power when it shouldn't might feel warm to the touch even when the car is off.

How to verify and confirm the issue

Confirming a parasitic draw requires a systematic approach, often involving a multimeter. Before diving into complex diagnostics, rule out the basics.

  1. Check battery health: Have the battery load tested at an auto parts store or with a dedicated battery tester. A weak or old battery might simply not hold a charge, even without a draw.
  2. Inspect battery terminals and cables: Ensure they are clean, tight, and free of corrosion. Loose or corroded connections can prevent proper charging and lead to poor starting.
  3. Perform a parasitic draw test (multimeter required):
    • Ensure the car is completely off, doors closed, and all accessories are turned off. Wait 15-30 minutes for all modules to 'go to sleep.'
    • Disconnect the negative battery cable.
    • Set your multimeter to measure amperage (typically 10A or 20A DC range).
    • Connect the multimeter's red lead to the negative battery post and the black lead to the disconnected negative battery cable.
    • Read the amperage. A healthy parasitic draw for most modern vehicles, including your 2017 Impreza, should be less than 50 milliamps (0.05 amps). Anything significantly higher indicates a problem.
  4. Check charging system: With the engine running, measure the voltage across the battery terminals. It should be between 13.5 and 14.5 volts. If it's outside this range, the alternator might not be charging the battery correctly. You can find more general information on diagnosing charging issues in our repair guides.
  5. Scan for diagnostic trouble codes (DTCs): Even without an illuminated check engine light, a standard OBD-II scanner can sometimes reveal codes related to low voltage or module communication issues that might point to a problematic circuit. For a deeper dive into common codes, visit our OBD-II codes hub.

Common causes (most likely first)

For your 2017 Subaru Impreza, specific components or common issues are often the culprits behind excessive battery drain.

  • Faulty or aftermarket accessories: Aftermarket stereos, alarms, remote starters, dash cams, or poorly installed accessories are frequent sources of parasitic draws.
  • Interior lights or trunk light staying on: A door switch, glove box light switch, or trunk light switch might be faulty, keeping a light on even when closed.
  • Infotainment system issues: The Starlink infotainment system, being a complex electronic module in the 2017 Impreza, can sometimes fail to power down correctly, leading to a constant draw.
  • Keyless entry/ignition system modules: Components related to the smart key system can sometimes stay active, consuming power.
  • Alternator diode failure: A failing diode in the alternator can allow current to flow back to the alternator when the engine is off, draining the battery.
  • Faulty Body Control Module (BCM) or other control modules: While less common, a malfunctioning BCM, anti-lock brake module, or other electronic control unit (ECU) can fail to enter sleep mode.
  • Blown fuses (less common for parasitic draw, but can indicate a short): A short circuit can cause a fuse to blow, but a component on that circuit could still be drawing power if the short is intermittent or if the fuse is bypassed.

What is different on this year and model

The 2017 model year marked the introduction of the fifth generation Impreza, bringing with it a host of new technologies that, while enhancing the driving experience, also introduce new potential points of failure for electrical systems. The Starlink infotainment system and more integrated electronic control modules (ECUs) are more complex than previous generations. These systems require precise power management, and any glitch can lead to a module failing to

This guide is not a substitute for OEM service procedures; use a qualified technician for safety-critical repairs.

Frequently asked questions

How urgent is this problem?

If symptoms are worsening or safety systems are affected, diagnose soon; minor issues can often wait for a scheduled service visit.

Can I drive with this issue?

Short trips may be acceptable for some faults, but stop driving if you notice overheating, loss of braking, steering problems, or strong fuel smells.

Do I need a dealer scan tool?

A basic OBD-II scanner helps confirm codes; some steps still need visual checks and meter tests described above.

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