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DTC codes / BMW codes / P1145

P1145 · BMWSolenoid Valve Running Losses Control Circuit Electrical

P1145 on BMW vehicles indicates that the engine control module (DME) has detected an electrical fault in the circuit for the solenoid valve that controls running losses from the fuel tank ventilation system. The computer monitors the current flow through the valve and sets this code when the measured current is outside the expected range, either too high (short to ground) or too low (open circuit or short to power).

SystemPowertrain
Code typeBMW specific
SeverityLow
Fix difficultyIntermediate
AreaFuel and air metering

Symptoms you may notice

  • Illumination of the check engine light, often with no other noticeable symptoms.
  • A faint fuel or hydrocarbon odor around the vehicle, especially after refueling or when parked.
  • Slight rough idle or hesitation in some cases if the valve is stuck open and unmetered air enters the intake.
  • Increased evaporative emissions, which may be detected during an emissions inspection.
  • In rare instances, a whistling or clicking noise from the engine bay if the solenoid is stuck or chattering.

Common causes, most likely first

  1. Failed solenoid valve (open or shorted internal coil).
  2. Damaged or corroded wiring harness connector at the valve.
  3. Broken, chafed, or pinched wires between the DME and the solenoid valve.
  4. Loose or corroded ground connection for the valve circuit.
  5. Faulty DME driver circuit (rare but possible after other causes are ruled out).
  6. Contamination or sludge in the valve causing mechanical sticking, which can overload the electrical circuit.

How to diagnose and fix it

  1. Use a scan tool to confirm P1145 is active and check for related evaporative emission (EVAP) codes.
  2. Visually inspect the solenoid valve connector and wiring for corrosion, damage, or loose pins.
  3. Measure the resistance of the solenoid valve with a multimeter and compare to BMW specifications; replace if out of range.
  4. Check for battery voltage at the valve connector with the key on and engine off, and verify the ground circuit integrity.
  5. Perform a wiggle test on the wiring harness while monitoring the valve with a scan tool or multimeter to detect intermittent faults.
  6. If wiring and valve are good, test the control signal from the DME; repair or replace the DME only as a last resort.
  7. Clear the code and perform a drive cycle to verify the repair, ensuring the monitor runs and the code does not return.

Don't overlook the fuel tank breather valve

  • The solenoid valve in question is often called the fuel tank breather valve or purge valve; a seized valve can cause both electrical and mechanical faults that set P1145.
  • A sticking valve may test fine electrically when cold but fail when hot, so resistance checks should be done at operating temperature when possible.
  • Corrosion inside the connector pins is a common cause on older BMWs, even when the valve itself is good, so always inspect the terminals closely.
  • This code can be set by a momentary voltage spike or low battery, so check for a stable power supply and clear the code once to see if it returns before replacing parts.
  • Do not confuse P1145 with P0440-series EVAP codes; P1145 is specific to the electrical circuit of the running losses valve, not the entire EVAP system.

Can I keep driving with P1145?

You can generally continue driving with this code because it does not affect engine performance or safety, but avoid ignoring it for long as it may increase emissions and could lead to a failed emissions test. Have the circuit inspected soon to prevent potential fuel vapor leaks.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for BMW vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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