What P0243 means
The wastegate lets exhaust bypass the turbine to limit boost; actuator A is either a pulse-width-modulated solenoid on a pneumatic wastegate can or an electric actuator with a position sensor.
How the engine computer detects it
P0243 is the general circuit fault of actuator A. GM uses it for an open circuit: with the driver off, more than 200 kΩ between output and ground in 10 of 20 samples sets it with the warning light in the first trip (older modules: two trips). Ford uses P0243 on its electric wastegates as the collective code for open and short circuits (0.4 s), together with P2ABD for driver overcurrent or overheating. Boost control is then switched off and only the spring-set base boost remains – less power, but no risk of overboost.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on
- Clearly less power, boost only at base level
- Sluggish acceleration, turbo lag
- Reduced engine power message possible
Common causes
- Connector at the wastegate valve or actuator loose, corroded or with spread contacts Most likely
- Valve coil or electric actuator winding open Possible
- Supply voltage to the valve missing (ignition, relay, fuse) Possible
- Broken control wire between module and valve Possible
- Driver stage in the engine module faulty Less likely
How to diagnose P0243
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: wastegate actuator a, wastegate solenoid valve, actuator wiring.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 2
- Fuel and air metering (injector circuit)
- 43
- Specific fault
Questions drivers ask
Can I drive with code P0243?
Drive gently and only as far as you need to. The engine computer may limit power to protect the engine, so avoid highways and heavy traffic until it's fixed. If the check engine light starts flashing, pull over.
Will my car pass an emissions inspection with P0243?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Can I fix P0243 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: medium. Start with the cheapest checks before replacing expensive parts.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.