P0249 Code is a generic OBD-II powertrain diagnostic trouble code that indicates the ECM or PCM has detected a low electrical condition in the circuit controlling the Turbocharger/Supercharger Wastegate Solenoid B.
The fault does not automatically mean that the turbocharger or supercharger itself has failed. The problem may be caused by the Wastegate Solenoid B, wiring, connector, fuse, power supply, control circuit, or, less commonly, the ECM/PCM.
The exact circuit design, solenoid location, voltage strategy, resistance specification, and diagnostic procedure can vary by manufacturer, engine, and model year. Always verify the wiring diagram and specifications for the exact vehicle.
P0249 Code Definition
Code type: Generic OBD-II Powertrain Code.
System: Turbocharger/Supercharger Boost Control.
Responsible component: Wastegate Solenoid B and its electrical control circuit.
The word Low refers to an abnormal electrical condition detected in the solenoid control circuit. It does not automatically mean that turbocharger boost pressure is physically low.
P0249 Code Severity
Moderate. The vehicle may experience reduced boost or reduced engine performance.
Limited driving may be possible if the engine operates normally and no severe symptoms are present.
Incorrect boost control, reduced performance, and possible additional faults.
Symptoms of P0249 Code
- Check Engine Light illuminated.
- Reduced engine power.
- Slow acceleration.
- Loss of turbocharger or supercharger boost.
- Reduced throttle response.
- Reduced-power or limp mode on some vehicles.
- Boost pressure lower than expected.
- Difference between commanded and actual boost pressure.
- Hesitation during acceleration.
- Reduced fuel economy in some applications.
- Additional boost-control or electrical codes.
Common Causes of P0249 Code
- Faulty Turbocharger/Supercharger Wastegate Solenoid B.
- Open circuit in the solenoid wiring.
- Short to ground in the control circuit.
- Damaged or overheated wiring.
- Corroded or loose electrical connector.
- Backed-out or damaged connector terminals.
- Blown fuse where applicable.
- Loss of power supply to the solenoid.
- High resistance in the circuit.
- Poor electrical connection.
- Damaged harness near the turbocharger or exhaust system.
- Aftermarket wiring or boost-control modifications.
- ECM/PCM control-driver fault, which is less common.
Where Is the P0249 Wastegate Solenoid B Located?
The Wastegate Solenoid B controls or regulates the wastegate/boost-control system on applicable turbocharged or supercharged engines.
The exact physical location varies considerably between vehicles. The solenoid may be mounted near the turbocharger, intake system, engine, vacuum-control system, or on a bracket connected to the boost-control plumbing.
On systems using multiple boost-control solenoids, the manufacturer identifies the circuits as "A" and "B." The physical location of Solenoid B must therefore be confirmed using the vehicle-specific service information rather than assuming that it is always in the same position.
Component Responsible for P0249 Code
The primary component associated with P0249 Code is the Turbocharger/Supercharger Wastegate Solenoid B and its electrical circuit.
The solenoid receives electrical control from the ECM/PCM and participates in the boost-control strategy. Depending on the system design, the ECM/PCM may control the solenoid by switching power, ground, or a pulse-width-modulated signal.
Because circuit designs differ, the solenoid itself should not be replaced until the power supply, wiring, connector, and control circuit have been tested.
How to Fix P0249 Code
The correct repair depends on the actual cause found during diagnosis.
- Replace the faulty Wastegate Solenoid B when testing confirms an internal electrical failure.
- Repair an open or damaged wire.
- Repair a shorted control circuit.
- Repair corroded or damaged connectors.
- Restore the correct solenoid power supply.
- Repair poor electrical connections or terminals.
- Replace a blown fuse after identifying why it failed.
- Repair heat-damaged wiring near the turbocharger or exhaust.
- Repair the ECM/PCM driver circuit only when testing confirms the module is responsible.
Common Repair Mistakes for P0249 Code
Replacing the Turbocharger
P0249 Code is primarily an electrical circuit fault. Replacing the turbocharger without testing the Wastegate Solenoid B circuit can result in an unnecessary and expensive repair.
Replacing the Solenoid Without Testing the Wiring
A failed solenoid is possible, but an open wire, short to ground, poor connector, or missing power supply can produce the same code.
Confusing Low Circuit Voltage With Low Boost Pressure
The word Low in P0249 describes an electrical condition monitored by the ECM/PCM. It does not by itself prove that the engine has physically low turbocharger boost.
Replacing the ECM Too Early
An ECM/PCM driver fault is possible but less common. The complete circuit should be tested before condemning the control module.
P0249 Code Repair Cost
Approximately $50–$150+.
Approximately $50–$250+.
Approximately $100–$400+ depending on vehicle and parts availability.
Can be considerably more expensive depending on the vehicle and repair required.
These are general estimates only. Actual repair costs vary according to vehicle, engine, parts prices, labor rates, accessibility, and the actual cause of the fault.
Can You Drive With P0249 Code?
Limited driving may be possible when the engine is running normally and there are no severe symptoms. However, the vehicle may have reduced boost, reduced power, or a protective operating strategy.
If the vehicle has severe power loss, abnormal engine operation, excessive smoke, unusual turbocharger noises, or additional warning lights, diagnosis should be performed promptly.
How to Diagnose P0249 Code
1. Scan for All Diagnostic Trouble Codes
Use an OBD-II scanner to confirm P0249 Code and record all stored, pending, and manufacturer-specific codes.
If another wastegate-solenoid code such as P0245, P0246, P0247, P0248, or P0250 is also present, consider whether the affected circuits share a fuse, relay, power supply, ground, or wiring section.
2. Check Freeze-Frame Data
Record engine RPM, calculated load, vehicle speed, throttle position, boost-related parameters, and other available information from the moment the code was stored.
3. Identify Wastegate Solenoid B
Use the vehicle-specific wiring diagram and service information to identify the correct Wastegate Solenoid B, its connector, power circuit, control circuit, and ECM/PCM terminals.
4. Inspect the Wiring and Connector
Inspect the harness for melted insulation, broken wires, chafing, corrosion, loose terminals, water intrusion, and previous repairs.
Pay particular attention to wiring routed close to the turbocharger, exhaust manifold, turbine housing, or other high-temperature areas.
5. Check the Fuse and Power Supply
If the solenoid circuit uses a fuse or shared power supply, check it according to the manufacturer's wiring diagram.
A blown fuse should not simply be replaced repeatedly. Determine what caused the excessive current or short circuit.
6. Test Wastegate Solenoid B Resistance
With the solenoid disconnected and the ignition off, measure its resistance when the manufacturer specifies this test.
Compare the measurement with the exact vehicle specification. Do not apply one universal resistance value to every wastegate solenoid.
7. Check for a Short to Ground
Because P0249 indicates a low electrical condition, inspect the control circuit for an unintended short to ground.
The correct test method depends on whether the solenoid is power-switched, ground-switched, or PWM controlled.
8. Check Circuit Continuity
Test the wiring between the Wastegate Solenoid B and ECM/PCM according to the manufacturer's procedure.
High resistance, an open circuit, or intermittent continuity can prevent the control module from correctly operating or monitoring the solenoid.
9. Check the Control Signal
Where supported, use a scan tool to command the wastegate solenoid and observe whether the solenoid responds.
Some systems use a PWM control signal, so a multimeter alone may not provide enough information to evaluate the complete control waveform.
10. Test the ECM/PCM Only After the Circuit Is Verified
If the solenoid, fuse, power supply, wiring, connector, and grounds all test correctly, follow the manufacturer's procedure for testing the ECM/PCM driver.
The ECM/PCM should not be replaced based on P0249 Code alone.
P0249 Diagnostic Signal Flow
↓
Wastegate Solenoid B
↓
Control Circuit
↓
ECM / PCM
↓
Boost Control Monitoring
The exact power and control arrangement varies between manufacturers. Some systems provide power to the solenoid and use the ECM/PCM to control the ground side, while other designs use different control strategies.
P0249 OBD Live Data
Depending on the vehicle and scan tool, useful parameters may include:
- Commanded boost pressure.
- Actual boost pressure.
- Wastegate command.
- Wastegate duty cycle.
- Engine RPM.
- Throttle position.
- Calculated engine load.
- Manifold pressure.
- Turbocharger pressure-related PIDs.
Live Data can help determine whether the boost-control system is responding to commands, but an electrical circuit fault should also be tested directly when necessary.
P0249 Code and Electrical Testing
A digital multimeter can help test the Wastegate Solenoid B circuit.
- Identify the correct solenoid terminals.
- Measure solenoid resistance where specified.
- Verify the power supply.
- Check the control circuit.
- Check continuity.
- Check for a short to ground.
- Perform voltage-drop testing where appropriate.
Always use the vehicle-specific wiring diagram because wire functions and control strategies vary between manufacturers.
P0249 OEM Information
P0249 is a standardized generic OBD-II code, but manufacturers may use slightly different wording or diagnostic strategies for the same underlying fault.
Depending on the manufacturer, the description may refer to a turbocharger wastegate solenoid, supercharger wastegate solenoid, boost-control solenoid, or another equivalent boost-control component.
The exact solenoid identification, circuit configuration, connector pinout, voltage specification, and diagnostic thresholds must therefore be confirmed using OEM service information for the specific vehicle.
P0249 vs Related P024x Codes
Turbocharger/Supercharger Wastegate Solenoid B
Turbocharger/Supercharger Wastegate Solenoid B Range/Performance
Turbocharger/Supercharger Wastegate Solenoid B Low
Turbocharger/Supercharger Wastegate Solenoid B High
These codes belong to the same general boost-control family, but they do not mean the same thing. P0249 specifically indicates a low electrical condition in the Solenoid B circuit.
Related P0249 Codes
- P0247 – Turbocharger/Supercharger Wastegate Solenoid B.
- P0248 – Turbocharger/Supercharger Wastegate Solenoid B Range/Performance.
- P0250 – Turbocharger/Supercharger Wastegate Solenoid B High.
These codes are provided for diagnostic comparison only. They should not be interpreted as alternative definitions of P0249 Code.
FAQ About P0249 Code
What does P0249 Code mean?
P0249 Code means the ECM/PCM has detected a low electrical condition in the circuit controlling the Turbocharger/Supercharger Wastegate Solenoid B.
Does P0249 mean the turbocharger is bad?
No. P0249 is primarily associated with the wastegate-solenoid control circuit. The solenoid, wiring, connector, fuse, power supply, control circuit, and ECM/PCM should be tested before condemning the turbocharger.
What causes P0249 Code?
Possible causes include a faulty Wastegate Solenoid B, open wiring, short to ground, damaged connector, blown fuse, poor power supply, high resistance, or an ECM/PCM driver problem.
What is the difference between P0249 and P0250?
P0249 indicates a low electrical condition in the Wastegate Solenoid B circuit, while P0250 indicates a high electrical condition. Their diagnostic tests can therefore be different.
Can wiring cause P0249?
Yes. Open wiring, damaged insulation, short circuits, corrosion, loose terminals, and heat damage can all interfere with the Wastegate Solenoid B circuit.
Can I drive with P0249?
Limited driving may be possible if the engine operates normally, but reduced boost or reduced power may occur. Severe symptoms should be diagnosed promptly.
How do I fix P0249 Code?
Confirm the code, identify the correct Wastegate Solenoid B, inspect the wiring and connector, check the fuse and power supply, test the solenoid, verify the control circuit, and test the ECM/PCM only when the other components have been confirmed good.
Is P0249 a serious code?
P0249 is generally a moderate-severity fault because it can affect boost control and engine performance. The severity depends on the vehicle and the underlying electrical problem.