P0243: How to Diagnose & Fix — Turbocharger/Supercharger Wastegate Solenoid "A" Malfunction
16 vehicles · 4 makes · $100-$12,000 repair
How to diagnose and fix P0243: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
BMW 3 Series · 2012–2018
The wastegate actuator and boost solenoid can fail, causing boost control issues, over-boost conditions, or under-boost faults. The N55 uses an electronic wastegate that can develop problems.
Common Symptoms
- Check engine light with boost codes
- Limp mode/reduced power
- Inconsistent boost
- Turbo lag
- Over-boost situations
How to Fix
Diagnose boost system for proper operation. Replace wastegate actuator or boost solenoid as needed. Check vacuum lines for leaks. Software update may address some issues.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine BMW pressure converter / boost-control solenoid 11747649407OEM11747649407
Fitment: N55 BMW 335i/335i xDrive applications using the pneumatic-wastegate pressure-converter system; verify VIN, build date, turbo/wastegate type, and failed component before ordering..
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (1)
BMW M3 · 2015–2018
The F80 M3's S55 engine uses a Y-shaped plastic charge pipe connecting both turbos to the throttle body. Under boost pressure, especially with tuning or on track, the plastic charge pipe can develop hairline cracks near the mounting brackets and turbo connections. These cracks often open under boost, allowing compressed air to escape.
Common Symptoms
- Reduced engine power/sluggish acceleration
- Hissing sounds under acceleration (boost leak)
- Increased wastegate duty cycle (WGDC reaching 100%)
- Check engine light with boost pressure-related codes
- Unable to reach target boost pressure
How to Fix
Replace with aluminum aftermarket charge pipes (ARM Motorsports, FTP, AMS Performance, BMS). Silicone couplers at connection points for improved sealing. Regular visual inspection of charge pipes for cracks.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- VRSF S55 charge-pipe upgrade kit 10801050Cross-ref10801050
Confirmed failed S55 hot-side charge-pipe replacement or disclosed performance-use upgrade. Fitment: 2015-2018 F80 M3 S55 after vehicle-selector confirmation.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (1)
BMW M240i · 2017–2024
The B58 engine uses a plastic charge pipe to route compressed air from the turbocharger to the throttle body. Under sustained high boost conditions, the factory plastic charge pipe can crack, split, or blow off, resulting in an immediate and total loss of boost pressure. This failure can occur on completely stock vehicles as the plastic degrades from repeated heat cycling over time, but is accelerated by any ECU tune that increases boost pressure.
Common Symptoms
- Sudden and complete loss of boost pressure
- Loud pop or hissing sound from engine bay
- Check engine light with boost pressure codes
- Significant power loss, especially above 3,000 RPM
- Turbo whistle or whooshing noise under acceleration
How to Fix
Replace the factory plastic charge pipe with an upgraded aluminum aftermarket unit from manufacturers like Burger Motorsports, VRSF, or FTP Motorsport. If the failure occurs on a stock car, BMW may cover repair under warranty. After replacement, inspect the intercooler boots and all charge air connections for damage.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- BMS Elite aluminum Gen-1 B58 F22/F23 M240i charge pipe
Confirmed failed F-chassis Gen-1 B58 charge-pipe replacement. Confirm chassis and engine selection on the product page; not approved for G42..
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (1)
Audi SQ5 · 2014–2018
Audi S8 · 2013–2024
Find P0243 by make
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P0243 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0243 mean?
P0243 stands for "Turbocharger/Supercharger Wastegate Solenoid "A" Malfunction." This code indicates a general fault with turbocharger/supercharger wastegate solenoid "A," which the engine control module uses to manage boost pressure. The computer has detected the solenoid or its circuit is not responding correctly (open, shorted, or out of expected operating range). Because it governs boost, a fault can lead to overboost or underboost, reduced power, or a limp mode.
What are the most common causes of P0243?
The most common causes of P0243 are: Failed or sticking wastegate solenoid, Open or shorted wiring in the solenoid circuit, Corroded or damaged electrical connector, Mechanical wastegate sticking or binding, Vacuum/boost hose leaks or blockage, Faulty ECM/PCM solenoid driver (rare). The specific cause varies by vehicle.
How much does it cost to fix P0243?
Repair costs for P0243 range from $100 to $12,000, depending on the vehicle and root cause.
Which vehicles are affected by P0243?
Au7o has documented P0243 across 16 vehicle models from 4 manufacturers: Audi, BMW, Ford, Toyota.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.