P0243: The wastegate control solenoid for your turbocharger has failed
Turbocharger/Supercharger Wastegate Solenoid A Malfunction
There is a fault in the turbo wastegate solenoid, so boost control is unpredictable. Stop driving and have it towed for diagnosis.
Stop driving and get help if
- The check engine light is flashing
- The temperature gauge runs high, or you see steam (overheating)
- The car loses power, hesitates badly or stalls
- You smell burning or see smoke
- A brake warning light comes on, or the brakes feel different
Pull over as soon as you can, turn the engine off, and call a tow or roadside help.
What it means
The wastegate solenoid, also called a boost control solenoid, is the electronic valve that controls air pressure to the wastegate actuator. The PCM adjusts this solenoid dozens of times per second under boost to hit the target pressure. P0243 means the PCM detected an electrical fault in the solenoid circuit, such as an open, short, or out-of-range resistance. Without working solenoid control, the wastegate defaults to its spring pressure, which usually means either full boost or no boost depending on the actuator design.
Common causes
- Failed boost control solenoidThe solenoid coil burns out or the valve sticks. Most common cause.
- Open or short in the solenoid wiring harnessThe harness near the turbo runs in a high-heat environment and cracks over time.
- Corroded solenoid connectorOil and heat degrade the connector at the solenoid over time, breaking the circuit.
- PCM output driver failureThe PCM drives the solenoid ground. A failed driver looks identical to a solenoid failure without testing.
What the fix could involve
From the cheaper fix to the bigger one. Prices depend on your car, your area and the shop, so ask for a written quote that names the part and the labor before you approve it.
- Boost control solenoid replacement
- Wiring or connector repair
- PCM diagnosis and replacement
Symptoms
- Check engine light on
- Possible limp mode limiting boost
- Either unusually low power (wastegate stuck open) or overboost risk (stuck closed)
- Possible turbo surge or unusual turbo sounds
What to do next
Measure the solenoid resistance at the connector. Most boost control solenoids read between 15 and 30 ohms. An out-of-spec reading confirms a bad solenoid. If resistance is normal, check the harness for damage and confirm the PCM is supplying the correct ground signal. The solenoid is usually accessible and relatively affordable compared to turbocharger work.
Lewis reads P0243 alongside any related boost and wastegate codes, so you can see whether it is a circuit fault on its own or already causing an overboost or underboost code. Get Lewis on the App Store or Google Play.
Related codes
FAQ
- What happens if I drive with P0243?
- The car may enter limp mode and limit boost, which is the better outcome. The worse outcome is uncontrolled overboost if the wastegate defaults closed. Do not risk it: have it towed.
- Is the boost control solenoid the same as the wastegate actuator?
- No. The solenoid is the electronic valve that controls air pressure. The actuator is the mechanical device that opens and closes the wastegate flap. P0243 is about the solenoid.
- Can I clean the solenoid instead of replacing it?
- Sometimes blowing out a stuck solenoid with compressed air helps briefly, but if the coil is burned or the valve seat is worn, replacement is the correct fix.
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