Damaged, chafed or corroded wiring to the solenoid valve (open circuit, short to earth or short to supply); Poor connection at the solenoid valve connector or engine control unit connector; Failed solenoid valve coil (open or shorted winding); Cracked or blocked vacuum hoses to the valve causing related faults alongside the circuit fault; Blown fuse or fault in the supply or earth feed to the valve; Internal fault in the engine control unit driver circuit.

P1103

Pressure Sources Switching Solenoid Valve Circuit.

Subaru
Powertrain
Manufacturer code
Low severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
1: AreaFuel and air metering
03: FaultThe specific fault in that area

What it means

On Subaru, P1103 means the engine control unit has found a fault in the electrical circuit of the pressure sources switching solenoid valve. This valve switches a pressure sensor between different pressure sources, such as intake manifold and atmosphere, on models that use the system. The control unit sets the code when the solenoid circuit voltage or current is not what it expects when commanded. Exact valve location and function vary by model and year.

Symptoms

Check engine light on
Usually no obvious driveability change
Possible slightly rough idle or hesitation on some models
Possible incorrect load or altitude compensation affecting fuelling
Other pressure-related or evaporative system codes stored alongside

Possible causes

Damaged, chafed or corroded wiring to the solenoid valve (open circuit, short to earth or short to supply)likely
Poor connection at the solenoid valve connector or engine control unit connectorlikely
Failed solenoid valve coil (open or shorted winding)likely
Cracked or blocked vacuum hoses to the valve causing related faults alongside the circuit faultpossible
Blown fuse or fault in the supply or earth feed to the valvepossible
Internal fault in the engine control unit driver circuitrare

How to diagnose

Read all stored and pending codes and note any related pressure sensor, evaporative or vacuum codes
Review freeze frame data to see the engine conditions when the fault set
Locate the pressure sources switching solenoid valve for the specific model and inspect its connector, wiring and hoses for damage, corrosion, heat or chafing
Check the relevant fuse and confirm the supply voltage and earth at the valve connector against the workshop data
Measure the solenoid coil resistance and compare it with the manufacturer specification
Activate the valve with a suitable diagnostic function if available, listening and feeling for operation
Check wiring continuity and insulation between the valve connector and the control unit, using the model wiring diagram
Clear the code and road test to see if it returns

How to fix

Repair or replace damaged wiring and terminals in the solenoid circuit
Clean or replace the corroded or loose connector
Replace the solenoid valve if its resistance or operation is out of specification
Replace cracked, split or disconnected vacuum hoses
Restore the supply or earth feed and replace any blown fuse after finding why it failed
Have the engine control unit checked or replaced only after wiring and valve are proven good

Can I keep driving?

Low severity

The car can normally be driven while you arrange a repair, as this is a circuit fault with little immediate risk. Book it in soon, especially if the car runs roughly or has to pass an emissions test.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.