P0249 Code Meaning and Next Steps

First checks take 10 minutes for basic checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The vehicle suddenly runs much worse, loses power sharply, or the check-engine light starts flashing.
!There is a strong smell, smoke, overheating, or any symptom that suggests a real-time safety problem rather than a stored code alone.

If the light is steady and the vehicle still drives normally: Often yes for a short time, but it should not be ignored if drivability changes are obvious.

What to check first

Step-by-step checks

1
Safety first
Let the engine cool before touching turbo, exhaust, or charge-air parts
2
Free - no tools
Check whether the fault appears only in certain boost states or only under load
3
Basic tool needed
Inspect the second solenoid, vacuum lines, and actuator movement for obvious issues
4
Basic tool needed
Use live data if available to see whether the requested change matches the actual boost change
5
Basic tool needed
Look for oil residue, cracking, or loose fitment on the secondary control hose set
6
Basic tool needed
Confirm whether the vehicle actually uses a separate B-path control strategy before replacing parts

If the code returns

-If the secondary path is leaking, repair that before buying a new solenoid.
-If the secondary actuator sticks, replace or service the mechanical side first.
-If the system otherwise boosts normally, the secondary path may only fail in one operating band.

Background

What this code means

P0249 is a generic OBD-II code for a secondary boost control range or performance issue.

The ECU is not seeing the second boost path respond the way it expects. That can come from a valve that is weak, a hose that leaks, or an actuator that does not move when commanded.

Diagnosis

Common causes

Most common

Secondary boost control solenoid wear

The valve may still work sometimes but not well enough to satisfy the range check.

Common

Vacuum leak in the B-path

A leak can stop the second boost-control path from changing boost properly.

Common

Sticking actuator

If the actuator movement is lazy, the ECU may see an out-of-range response.

Possible

Sensor feedback mismatch

The control hardware may be fine, but a bad reading can make it look out of range.

Avoid these mistakes

What not to do

xDo not replace the main turbo before checking the secondary path itself.
xDo not ignore a leak in the second control hose just because the primary path looks healthy.

Parts

Parts that may need replacing

PartTypical costNotes

Secondary boost control solenoid$40-$180Most relevant when the alternate valve is the weak point.

Vacuum hose set$10-$90Worth checking when the secondary control loop is leaking.

Secondary actuator or linkage$80-$350Important if the mechanical path is slow or sticking.

Related OBD codes

P0248

P0248 means the secondary boost control path has a fault.

P0250

P0250 means the secondary boost control circuit is reading too low.

P0251

P0251 means the secondary boost control circuit is reading too high.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0249 was seeded from dtcdb and then expanded around secondary boost-control range/performance faults, especially alternate solenoids and actuator movement issues.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0249 - The Secondary Boost Control Path Is Out of Range or Not Responding Properly