Subaru Factory Electrical Wiring Diagram

This page contains a complete electrical diagram of Subaru vehicles, including:

Fuse and relay diagram - location, ratings and purpose of fuses and relay blocks.

Ground loops - key connection points with ground for stable operation of electrical equipment.

Engine electrical system - wiring, sensors, injection control circuits, ignition and battery charging.

This section will help in diagnostics, repair and modernization of Subaru electrical equipment.

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Subarus are known for their reliability, but their electrical system is not immune to problems. Here are the most common faults:

1. Wiring problems

Oxidation of contacts and connectors - especially in regions with high humidity.

Wiring chafing - due to vibrations and mechanical impact.

Short or broken wires - often in the engine compartment or under the mats due to the age of the car.

2. Fuses and relays

Blown fuses - indicates an overload or short circuit.

Relay failure - leads to failure of the fuel pump, cooling fan or headlights.

3. Grounding problems

Bad contacts on the "ground" - cause unstable operation of electronics and dim headlights.

Oxidation of ground points - impairs the flow of current, which can lead to problems with starting the engine.

4. Sensors and electronics

Lambda probe (oxygen sensor) - affects fuel consumption and engine operation.

Mass air flow sensor (MAF) - when dirty, causes loss of power and ECU errors.

Throttle position sensor (TPS) – if it fails, the engine may run rough or not respond to gas.

ABS and ESP sensor – often fails due to dirt or damaged wires.

5. Battery and generator

Battery discharge – possible due to current leaks or a faulty generator.

Generator failure – leads to interruptions in the electrical system and battery charging.

How to avoid problems?

Regularly check the condition of the wiring and connectors.

Clean and treat the contacts with anti-corrosion compounds.

Use high-quality fuses and relays.

Periodically check the battery charge and the generator operation.