What it means
Generic fault on wastegate actuator A. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Wastegate actuator A controls the wastegate that regulates turbocharger boost by allowing exhaust gas to bypass the turbine. The module monitors the actuator A control circuit and boost response; P0243 indicates a fault associated with that actuator system, which can impair boost control.
Common causes
Most likely first.
- Wastegate actuator A failure
- Damaged wiring or connector
- Wastegate mechanism sticking
- Boost control hose or connection leak
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
How to diagnose it
- Review freeze-frame data and scan-tool data for the wastegate actuator A command and actual boost when the fault occurred.
- Inspect actuator A wiring and connectors for damage, loose terminals, corrosion, or signs of an electrical fault.
- Check the actuator linkage and wastegate mechanism for looseness, binding, or damage with the engine safely off.
- Inspect boost-control hoses and connections for leaks, cracks, or disconnection that could disrupt actuator operation.
- Test the actuator A circuit and actuator response using the manufacturer's diagnostic procedure before replacing parts.
Common fixes
- Reconnect or repair damaged wiring at wastegate actuator A.
- Replace a cracked or disconnected boost-control hose.
- Free or repair a sticking or damaged wastegate mechanism as specified by the manufacturer.
- Replace wastegate actuator A if circuit and response tests confirm it has failed.
Can I keep driving?
Because boost control may be unreliable and power may be limited, avoid hard acceleration, towing, and overtaking until the fault is diagnosed. Stop if the engine loses power sharply, runs abnormally, or produces heavy smoke.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.