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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 at a glance
CodeP0046
SystemEngine and transmission
GroupP00xx, Air, fuel and emissions
TypeGeneric: 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.

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 this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

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 the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

P0046 is a generic code, so it means the same on any make, for example on Alfa Romeo, Audi, Dacia, Kia, Opel / Vauxhall, Toyota. See what Final OBD does on your car in makes and models.

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.