Urgency: Low

Auto Start-Stop Light on a Subaru WRX

This is usually informational. Address it at your convenience.

What the Auto Start-Stop Light Means on a Subaru WRX

On the Subaru WRX, this 'A' symbol shows start-stop status. Green/available means it can stop the engine at rest; amber or crossed-out means conditions (battery charge, cabin temperature) are preventing it.

How Urgent Is the Auto Start-Stop Light?

In terms of priority, treat this as a low concern on your Subaru WRX. The single most useful thing you can observe is whether the Auto Start-Stop Light is steady or blinking: a steady light generally allows a careful drive to a safe location or a workshop, whereas a flashing light signals an active fault that can cause damage if you continue. Pay attention to changes in how the Subaru WRX drives, sounds, or smells, since those symptoms sharpen the diagnosis considerably.

Common Symptoms Alongside the Auto Start-Stop Light

When the Auto Start-Stop Light shows up on a Subaru WRX, it rarely arrives completely alone — there are usually subtle clues if you know where to look. Drivers often notice a change in how the Subaru WRX responds, an unfamiliar sound, or a warning message on the instrument cluster. Cataloguing these symptoms is not busywork; each one narrows the list of likely causes and helps a technician zero in on the real fault instead of replacing parts on a hunch.

  • Start-stop A symbol lit
  • Engine cuts out at a standstill
  • Amber/crossed symbol when unavailable
  • Follows the start-stop button

What Causes the Auto Start-Stop Light to Come On?

The Auto Start-Stop Light on the Subaru WRX can be triggered by several conditions, and experienced technicians work through them from most to least likely. Some causes are trivial and cost almost nothing to correct, while others require replacing a sensor or component. The list below reflects what actually turns this light on in the real world, so you can gauge whether you are likely facing a quick fix or a workshop visit.

  • Start-stop operating normally
  • Weak or aging battery preventing stops
  • High climate-control demand
  • Battery sensor fault
  • System switched off by the driver

How to Fix the Auto Start-Stop Light on a Subaru WRX

The right way to clear the Auto Start-Stop Light on a Subaru WRX is to fix the underlying cause, not just reset the symbol. Work through the steps below in order — they move from the simplest checks any driver can do to the diagnostic work best left to a scan tool. Following this sequence prevents the classic mistake of replacing expensive parts before ruling out the cheap, common problems first.

  1. Confirm whether start-stop was switched off
  2. Understand it disables when the battery is low or AC demand is high
  3. Have the battery and its sensor tested if it never works
  4. Replace an aged battery with the correct AGM/EFB type
  5. Scan for battery-management faults if needed

Is It Safe to Drive With the Auto Start-Stop Light On?

Whether it is safe to keep driving your Subaru WRX with the Auto Start-Stop Light on comes down to urgency (low) and behaviour. As a rule, if the light is red or flashing, or the Subaru WRX is running poorly, stop somewhere safe and arrange help rather than pushing on. If the light is amber and the car drives normally, you generally have time to reach a workshop — but 'have time' is not the same as 'ignore it', so book a check promptly.

Professional Mechanic Tips

Field notes from Marcus Vale, ASE-Certified Master Technician
Fitting the wrong battery type (a plain lead-acid instead of AGM/EFB) is a classic reason start-stop quits working after a battery change.

Frequently Asked Questions

Why is the Auto Start-Stop Light on in my Subaru WRX?

The Auto Start-Stop Light illuminates on a Subaru WRX when the vehicle detects a condition in the related system that is outside its normal range. The exact reason can vary from something as minor as a loose connection to a component that needs replacing, which is why reading the stored trouble codes is the reliable way to know for certain.

Can I keep driving with the Auto Start-Stop Light on?

Short answer: sometimes, but not indefinitely. Given this indicator's low priority, respect the warning colour and the car's behaviour. When in doubt with your Subaru WRX, the safe choice is to stop and have it checked rather than risk further damage.

How much does it cost to fix the Auto Start-Stop Light on a Subaru WRX?

There is no single price for the Auto Start-Stop Light on a Subaru WRX; it ranges from a no-cost adjustment to a component replacement. The honest way to control cost is to diagnose the exact code before authorising any repair, so you only pay to fix what is actually wrong.

Will the Auto Start-Stop Light reset itself on a Subaru WRX?

If the trigger was temporary, a Subaru WRX may turn the Auto Start-Stop Light off automatically after a few drive cycles. If it remains lit, the vehicle is telling you the fault is still present, and the symbol will only go out for good once the cause is fixed.