P0045 — Turbocharger/Supercharger Boost Control Solenoid Circuit/Open
Moderate severityWhat it means
P0045 is stored when the engine control unit sees a fault involving the turbocharger/supercharger boost system. The boost system forces extra air into the engine for more power; the control unit commands a wastegate or vane position and watches the boost pressure that results. The “open” status means the control circuit is electrically broken — usually a cut wire, an unplugged connector or a failed driver.
Common symptoms
- The component does not respond to commands
- Loss of power or slow acceleration
- Limp mode under load
- Whistling or a boost-related noise
Likely causes
- Open or broken wire in the control circuit
- Unplugged or corroded connector
- A charge-air (boost) leak or split hose
- A sticking wastegate, VNT mechanism or boost-control valve
What to check first
- Check circuit continuity and connector pins with the key off
- Pressure-test the charge-air pipes for leaks
- Compare commanded vs actual boost and check wastegate/VNT movement
Can you keep driving?
Often drivable with reduced power, but a stuck wastegate can over-stress the turbo — diagnose soon.
Frequently asked questions
What is the most common cause of P0045?
The most likely cause is: Open or broken wire in the control circuit. Several other faults can set P0045 as well, so confirm the real cause with live data and the checks above before replacing any parts.
Can I just clear P0045 and keep driving?
Clearing P0045 with an OBD2 scanner turns the warning light off, but if the underlying fault has not been repaired the code will usually come back within a few drive cycles. Fix the cause first, then clear the code to confirm the repair worked.
How serious is P0045?
P0045 is a moderate-severity code. The car is often still drivable, but have it diagnosed soon — the underlying problem can get worse and it may fail an emissions test.
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