P0243 on Audi: How to Diagnose & Fix
Turbocharger/Supercharger Wastegate Solenoid "A" Malfunction
4 Audi models · 4 documented issues · 2 critical · $300-$5,000 repair
P0243 on Audi by model: symptoms, diagnosis and fix
The SQ5 3.0T supercharged V6 shares supercharger nose bearing issues with the S4/S5. The intercooler water pump also fails, causing heat soak and reduced performance, especially in warmer climates.
Common Symptoms
- Whining from supercharger
- Reduced boost
- Heat soak power loss
- Supercharger belt squeal
- Intercooler pump code
- Elevated intake temps
How to Fix
Replace supercharger nose bearing kit. Replace intercooler pump if failing. Service supercharger belt tension.
Sources for this issue (1)
The S8 4.0T V8 shares coolant line issues with other 4.0T Audi models but the heavier sedan and higher power tune accelerate wear. Turbo oil and coolant line failures can cause expensive damage if not caught early.
Common Symptoms
- Coolant loss
- Turbo oil leak smell
- Overheating warning
- White exhaust smoke
- Low coolant light
- Oil in coolant or coolant in oil
How to Fix
Replace all turbo coolant and oil feed lines preventatively at 60,000 miles. Monitor coolant levels closely.
Sources for this issue (2)
The water-to-air intercooler system on the S5 3.0T uses an electric coolant pump that can fail, causing elevated charge air temperatures and reduced power. Heat soak becomes severe in warm climates.
Common Symptoms
- Heat soak power loss
- Reduced boost performance
- Intercooler pump fault code
- Elevated intake temps
- Sluggish acceleration in heat
- Check engine light
How to Fix
Replace intercooler coolant pump. Check intercooler lines for leaks and flush the circuit during replacement.
Sources for this issue (1)
The S7 with the 3.0T supercharged V6 (2012-2018) uses an electromagnetic clutch to engage the supercharger. Over time, the clutch disc wears out or the torsional isolator (damper) fails, creating a loud rattling, grinding, or "bag of marbles" sound from the front of the engine. This is most noticeable on cold starts or under load. A failed clutch prevents the supercharger from engaging, causing significant power loss. A failed isolator damages internal supercharger components, requiring complete supercharger replacement. Oil contamination accelerates wear—if oil becomes contaminated with dirt or debris, it causes premature failure of internal components. AudiWorld forums report failures between 60,000-120,000 miles, with repair costs of $1,500-$5,000.
Common Symptoms
- Loud rattling, grinding, or "marbles" noise from front of engine
- Noise most noticeable on cold start or light throttle
- Significant power loss (feels like naturally aspirated V6)
- Check engine light with underboost codes (P0234, P0299)
- Supercharger whine disappears (clutch not engaging)
- Belt squeal from supercharger pulley
- Metal debris in oil (severe internal damage)
How to Fix
If caught EARLY (noise but no power loss): Replace supercharger clutch ($1,500-$2,500 with labor). Clutch can be replaced without removing supercharger. If SEVERE (grinding + power loss): Replace complete supercharger assembly ($3,500-$5,000 installed). PREVENTION: Service supercharger oil every 40,000 miles despite Audi saying "lifetime." Change engine oil every 5,000 miles with high-quality synthetic. Avoid aggressive launches—gentle driving extends clutch life. Budget for this repair if buying a used S7.
Sources for this issue (1)
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 on a Audi?
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. On Audi it is documented across 4 models: SQ5, S8, S5, A7.
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 on a Audi?
Published repair estimates on Audi range from $300 to $5,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0243 on a different make?
View P0243 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.