P0046: Boost control solenoid: range or performance
The solenoid that controls turbo boost is not behaving as the ECU expects; usually a vacuum pipe, the solenoid or a poor connection.
| Code | P0046 |
|---|---|
| System | Engine and transmission |
| Group | P00xx, Air, fuel and emissions |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0046 means
On turbocharged or supercharged engines, an ECU-controlled solenoid sets how much boost is produced, by acting on the wastegate or on the variable geometry vanes. This code means the solenoid is getting current, but what it does does not match what the ECU asked for or the boost it measures. The engine may cut power to protect itself.
Most common causes
- Split, loose or misrouted vacuum or pressure pipe
- Poor contact or corrosion in the connector
- Sticking or slow solenoid
- Seized wastegate or variable geometry vanes
- Air leak in the hoses or intercooler
Symptoms
- Engine warning light on
- Clear loss of power (limp mode)
- Uneven or surging boost
- Sluggish acceleration
Can you drive with P0046?
With care You can drive, but with less power than normal, so take care when overtaking or joining fast roads. Have it looked at soon.
Open the bonnetthe in-depth explanation
How to check it
Find the solenoid (usually in the engine bay, with thin vacuum or pressure pipes) and check its connector and pipes. With a scan tool, watch desired and actual boost pressure in live data while accelerating.
How to read and clear P0046 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0046 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P0042 The lambda sensor heater control (bank 1, sensor 3) has an electrical fault
- P0043 Low signal in the heater of the third lambda sensor
- P0044 The lambda sensor heater control (bank 1
- P0045 Boost control solenoid: open circuit
- P0047 Boost control solenoid: circuit low
- P0048 Boost control solenoid: circuit high
- P0049 Turbocharger or supercharger turbine overspeed
- P004A The turbocharger boost control B has a broken or disconnected wire
- P0010 Camshaft A actuator control: open circuit (bank 1)
- P0011 Camshaft A timing over-advanced (bank 1)
- P0012 Camshaft A timing over-retarded (bank 1)
- P0013 Camshaft B actuator control: open circuit (bank 1)
To understand it properly
We explain how that system works, with drawings and no waffle, in our mechanics guide: Turbo and intercooler.
What does code P0046 mean?
On turbocharged or supercharged engines, an ECU-controlled solenoid sets how much boost is produced, by acting on the wastegate or on the variable geometry vanes. This code means the solenoid is getting current, but what it does does not match what the ECU asked for or the boost it measures. The engine may cut power to protect itself.
Can you drive with P0046?
You can drive, but with less power than normal, so take care when overtaking or joining fast roads. Have it looked at soon.
How do you clear P0046?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0046 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
