Parts for your 2012 Subaru Impreza-Ignition leads

2012 Subaru Impreza ignition leads: are they used?

For the 2012 Subaru Impreza (the FB20 2.0-litre petrol models commonly sold in Australia and New Zealand), traditional ignition leads aren’t used. This model runs a direct ignition, coil-on-plug setup, where each spark plug has its own pencil-style ignition coil mounted directly on top. That means there are no high-tension leads running from a central coil or distributor to the plugs.

Technical sources that document this configuration include:

• Subaru Factory Service Manual (2012 MY Impreza, Engine (FB) – Ignition System), which specifies a “Direct Ignition System” with individual coils and integrated igniters.
• Subaru Electronic Parts Catalogue (FAST/EPC) listings for 2012 Impreza FB20, which show individual ignition coils and spark plugs, with no spark plug wire/cable set.
• Ignition component catalogues from NGK and Denso for 2012 Impreza FB20, which list individual coil-on-plug units and iridium spark plugs, and do not list a lead/wire set for this application.

Why no leads? With coil-on-plug, the coil fires the plug directly, so there’s no need for long, high-voltage leads. This design improves spark energy at the plug, reduces electrical losses and radio interference, and helps the engine meet modern efficiency and emissions targets. It’s also less maintenance-heavy than older systems that relied on a single coil and a set of leads.

What should owners service instead? For a 2012 Impreza, the focus is on:

• Spark plugs: Replace at the logbook interval (typically around 100,000 kilometres for iridium plugs), or earlier if misfires, hard starts, or poor economy appear.
• Coils and boots: Under the bonnet, check each coil’s connector, body and rubber boot for heat cracking, carbon tracking or oil contamination (rocker cover gasket seepage can wick into boots). Replace any suspect coil or boot as a unit.
• Seating and sealing: Ensure coils are fully seated on the plugs and that seals are intact to keep moisture out.

Common symptoms pointing to coil or plug issues include a rough idle, hesitation on light throttle, higher fuel use, or a flashing check engine light with cylinder-specific misfire codes (P0301–P0304). A quick workshop check can confirm by swapping coils between cylinders to see if the fault follows the coil. Aftermarket “lead kits” marketed for earlier EJ-series Subarus won’t fit the 2012 Impreza FB20, because there’s simply nowhere to connect them.

Popular questions about 2012 Subaru Impreza ignition leads

Where are the ignition leads on a 2012 Subaru Impreza?
They aren’t fitted. The 2012 Impreza uses coil-on-plug ignition, so each spark plug has its own coil and there are no separate high-tension leads to find or replace. If you’re looking for service items, think spark plugs and the individual coils instead.

Can ignition leads be added or retrofitted to this model?
No practical reason or standard kit exists to retrofit leads. The engine management and hardware are designed for direct coil-on-plug firing. Retrofitting would add complexity and likely reduce reliability without any performance benefit.

What should be replaced during a “tune-up” if there are no leads?
Stick to spark plugs at the scheduled interval and inspect/replace any weak coils. It’s also smart to check coil connectors, look for oil around the plug tubes, and ensure the coils seat cleanly after plug changes.