Subaru EJ22 2.2L Engine Workshop Manual. Electrical System

Subaru EJ22 2.2L Engine Workshop Manual. Electrical System is a comprehensive guide to the electrical system of the EJ22 engine. Includes wiring diagrams, sensor locations, fuses and relays, and troubleshooting. Describes the operation of the ignition system, fuel injection, battery charging, and engine control unit (ECU). Useful for repairing, servicing, and troubleshooting electrical problems on Subaru vehicles with the EJ22 engine.

2200 cc – Subaru EJ22

Capacity: 2.2 liters (2212 cm³)

Configuration: 4-cylinder boxer

Fuel: Gasoline

Timing system: SOHC (single camshaft)

Power: 126–160 hp (depending on version)

Features:

Reliable and durable engine, used in Subaru Legacy, Impreza, Outback.

Naturally aspirated, without turbocharging.

Early versions had durable cast iron cylinder liners.

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The Subaru EJ22 engine (2.2L) is considered one of the most reliable in the EJ series, but, like any engine, it has its weak points.

1. Cylinder head gaskets

Although the EJ22 is less susceptible to overheating than the EJ25, the cylinder head gaskets can wear out over time.

Signs:

Engine overheating

Bubbles in the expansion tank

Exhaust odor in the coolant

Loss of coolant without visible leaks

How to avoid?

✔️ Use high-quality antifreeze and do not overheat the engine.

✔️ Monitor the cooling system and replace the cylinder head gaskets at the first sign of a leak.

2. Valve wear and clearance adjustment

Early versions of the EJ22 do not have hydraulic lifters, so valve clearances need to be adjusted regularly.

Signs:

Valve clatter when starting and idling

Loss of power

Unstable speed

How to avoid?

✔️ Check and adjust valve clearances every 80,000–100,000 km.

3. Oil leaks (seals, gaskets)

Over time, the following may leak:

Crankshaft seal

Valve covers

Sump gasket

Signs:

Oil stains under the car

Burnt oil smell from under the hood

Oil loss for no apparent reason

How to avoid?

✔️ Change seals and gaskets at the first sign of leakage.

✔️ Use high-quality oil and change it every 5,000–7,500 km.

4. Failure of ignition coils and spark plugs

Ignition coils and spark plugs can fail, especially when using low-quality fuel.

Signs:

Engine misfires

Loss of power

Increased fuel consumption

Check Engine errors (P030X – misfires)

How to avoid?

✔️ Use original coils and spark plugs (NGK, Denso).

✔️ Check the condition of the spark plugs every 30,000 km.

5. Fuel system (injectors, pump)

Over time, the injectors can become clogged, and the fuel pump can lose pressure.

Signs:

Difficult starting

Dips during acceleration

Uneven engine operation

How to avoid?

✔️ Use high-quality fuel and clean the injectors every 50,000 km.

✔️ Change the fuel filter every 40,000 – 50,000 km.