P0046 code meaning
Turbocharger/Supercharger Boost Control A Circuit Range/Performance
Powertrain system Generic code P00xx codes Check engine light
What P0046 means
"Boost control A" is the electrically driven actuator the engine control module uses to set boost pressure: depending on the engine a pulse-width modulated solenoid or vacuum converter at the wastegate, the control valve of variable turbine vanes, or an electric actuator with position feedback. The letters A and B denote two separate actuators, for example on the low- and high-pressure turbocharger of a two-stage system, not the cylinder banks. With this code the circuit is electrically intact, but the actuator does not follow the command plausibly: its actual position deviates too far or too long from the target, or its learned values do not fit. Boost is then too low or too high depending on where it sticks, often with reduced power.
P0046 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P0046
- Check engine light on
- Loss of power or reduced power mode
- Weak acceleration, noticeable turbo lag
- Overboost possible in rare cases
Common causes of P0046
- Most likelyTurbine vanes or wastegate linkage sooted or sticking
- Most likelyElectric actuator faulty
- PossibleActuator learn value invalid, e.g. after low battery voltage at start
- PossibleVacuum leak at a pneumatic actuator
- Less likelyActuator position sensor faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Boost control actuator aTurbochargerActuator position sensor
What each part of P0046 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 46 | The exact fault in that area. |
What to do next
- Note P0046 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0046
What does P0046 mean?
P0046 means "Turbocharger/Supercharger Boost Control A Circuit Range/Performance". "Boost control A" is the electrically driven actuator the engine control module uses to set boost pressure: depending on the engine a pulse-width modulated solenoid or vacuum converter at the wastegate, the control valve of variable turbine vanes, or an electric actuator with position feedback. It is a generic code, so it means the same on every make.
Is it safe to drive with P0046?
Drive gently and only to a workshop. With P0046 the car can go into limp mode (reduced power) to protect itself.
Will P0046 fail an emissions test?
Yes, it can. P0046 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0046 to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P0046 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.