Urgency: Low

Glow Plug Light (Diesel) on a Subaru XV

This is usually informational. Address it at your convenience.

What the Glow Plug Light (Diesel) Means on a Subaru XV

The glow-plug light on your diesel Subaru XV is your cue to wait a couple of seconds before starting in cold weather. A flashing light after the engine is running, however, indicates a fault the ECU wants checked.

How Urgent Is the Glow Plug Light (Diesel)?

How worried should you be? For the Glow Plug Light (Diesel) on a Subaru XV, the urgency is low. A good rule technicians rely on is 'colour plus behaviour': match the warning colour against how the car is actually performing. If the Subaru XV still drives normally and the light is steady, you usually have time to plan a proper diagnosis; if performance drops or the light flashes, err on the side of caution and stop safely.

Common Symptoms Alongside the Glow Plug Light (Diesel)

Alongside the Glow Plug Light (Diesel), Subaru XV owners commonly report a handful of related signs. Some are obvious, others easy to miss until you pay attention. Keeping a short mental (or written) log of what the Subaru XV does when the light is on gives whoever performs the repair a huge head start and can save you money on diagnostic time.

  • Light on briefly at cold start (normal)
  • Flashing light after warm-up (fault)
  • Hard starting when cold
  • Rough running or white smoke on cold mornings

What Causes the Glow Plug Light (Diesel) to Come On?

The Glow Plug Light (Diesel) on the Subaru XV 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.

  • Normal pre-heat cycle (steady, brief)
  • One or more failed glow plugs
  • Glow plug relay fault
  • Crankshaft/camshaft sensor issue
  • Related engine management fault

How to Fix the Glow Plug Light (Diesel) on a Subaru XV

To resolve the Glow Plug Light (Diesel) on your Subaru XV, resist the urge to simply disconnect the battery and hope it stays off. A warning that is cleared without addressing the cause almost always returns. The step-by-step approach below is the same logical order a professional follows on the Subaru XV: confirm the basics, read the stored codes, then target the actual fault.

  1. At cold start, wait for the light to go out before cranking
  2. If it flashes, scan for glow-plug and engine codes
  3. Test each glow plug for resistance/continuity
  4. Replace failed plugs (ideally as a set) and check the relay
  5. Clear codes and confirm easy cold starts

Is It Safe to Drive With the Glow Plug Light (Diesel) On?

Safe-to-drive depends on judgement, and here is the technician's version for a Subaru XV: respect the colour, respect the behaviour. Given this light's low urgency, treat any red or flashing warning as a stop-now signal. If everything feels normal and the light is amber, a short, cautious drive to a garage is typically fine, provided you do not delay the actual diagnosis.

Diagnostic Trouble Codes Linked to the Glow Plug Light (Diesel)

If you scan a Subaru XV showing this light, these are the OBD-II trouble codes most commonly associated with it. The code you actually retrieve is what pinpoints the repair.

CodeMeaning
P0335 Crankshaft Position Sensor Circuit
The crankshaft position sensor signal is faulty, which can cause stalling or a no-start condition.

Professional Mechanic Tips

Field notes from Marcus Vale, ASE-Certified Master Technician
Hard cold starts plus a flashing glow-plug light on a diesel Subaru XV usually means one or more plugs have failed — replace them as a set for even starting.
Do not ignore a flashing glow light; on many diesels it doubles as a general engine fault warning, so scan it rather than guessing.

Frequently Asked Questions

Why is the Glow Plug Light (Diesel) on in my Subaru XV?

Your Subaru XV turned on the Glow Plug Light (Diesel) after its self-diagnostics flagged an issue in that system. Because several different faults can trigger the same symbol, the smart first move is an OBD-II scan to pull the specific code before you spend any money.

Can I keep driving with the Glow Plug Light (Diesel) 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 XV, the safe choice is to stop and have it checked rather than risk further damage.

How much does it cost to fix the Glow Plug Light (Diesel) on a Subaru XV?

Repair cost for the Glow Plug Light (Diesel) on your Subaru XV depends entirely on the root cause. Because the same symbol covers cheap and expensive faults alike, a proper scan-based diagnosis is the best money you can spend — it turns a guess into a precise, fair quote.

Will the Glow Plug Light (Diesel) reset itself on a Subaru XV?

Occasionally, yes — a Subaru XV can extinguish the Glow Plug Light (Diesel) by itself when the monitored value returns to normal. But a light that keeps coming back is a clear sign of an unresolved issue that needs a proper diagnosis rather than repeated resets.