P0247 Turbocharger / Supercharger Wastegate Solenoid "B" Circuit Malfunction

P0247 – Turbocharger / Supercharger Wastegate Solenoid “B” Circuit Malfunction is a diagnostic trouble code that indicates the engine control module (ECM/PCM) has detected an abnormal condition in the electrical control circuit of wastegate solenoid “B.”

This code is associated with the electronic control of turbocharger or supercharger boost pressure. The wastegate system regulates how much exhaust gas reaches the turbocharger turbine, allowing the engine computer to control boost according to engine speed, load and operating conditions.

Unlike P0249, which specifically identifies a low electrical condition, P0247 is a more general circuit malfunction code. The ECM knows that something is wrong with the “B” solenoid circuit, but the code alone does not tell you whether the cause is the solenoid, wiring, connector, power supply, actuator or ECM.

What Does P0247 Mean?

A turbocharger can produce more boost than the engine needs if its operation is not controlled.

The wastegate helps regulate this boost. When the ECM determines that boost needs to be controlled, it operates the wastegate control system.

On systems using a wastegate solenoid, the solenoid controls pressure or vacuum going to the wastegate actuator, or participates in an electronic actuator control strategy.

The ECM monitors the electrical circuit while controlling the solenoid.

If the expected electrical behavior is not detected, it can store:

P0247 – Turbocharger / Supercharger Wastegate Solenoid “B” Circuit Malfunction

In practical terms, the ECM is reporting:

“The electrical circuit controlling wastegate solenoid B is not operating as expected.”

What Does “Circuit Malfunction” Mean?

The word “malfunction” is intentionally broad.

It does not necessarily mean that the solenoid itself is defective.

The ECM may detect a problem caused by:

• Open circuit

• Short to ground

• Short to power

• Excessive resistance

• Poor connector contact

• Damaged wiring

• Incorrect electrical load

• Faulty solenoid

• Power-supply problem

• Control-module problem

A mechanical problem with the wastegate can also produce boost-control symptoms, but an electrical circuit fault should be investigated first when P0247 is stored.

What Is a Wastegate?

The wastegate is part of the turbocharger boost-control system.

A turbocharger uses exhaust gas to spin a turbine. The turbine drives a compressor that increases the amount of air entering the engine.

As engine load increases, turbocharger speed and boost pressure can rise.

The wastegate provides a way to control this process by allowing some exhaust gas to bypass the turbine when necessary.

This prevents uncontrolled boost from continuing to increase.

The wastegate can be controlled through:

• A vacuum actuator

• A pressure actuator

• A wastegate solenoid

• An electronic actuator

• A combination of electronic and pneumatic components

The exact design depends on the engine.

What Does “B” Mean?

The “B” designation is manufacturer-specific.

Some engines use multiple boost-control solenoids, and the manufacturer identifies them as “A,” “B,” or another designation.

Therefore, P0247 does not tell you that every vehicle has the same physical component in the same location.

The exact Wastegate Solenoid “B” should be identified using the vehicle-specific wiring diagram and service information.

This is particularly important when several vacuum valves or turbocharger control solenoids are located near each other.

Common Symptoms of P0247

The symptoms can vary considerably depending on the vehicle and the failure mode.

Possible symptoms include:

• Check Engine Light

• Reduced engine power

• Poor acceleration

• Slow turbocharger response

• Lack of expected boost

• Excessive boost in some situations

• Hesitation during acceleration

• Poor throttle response

• Limp-home mode

• Unstable boost pressure

• Increased fuel consumption

• Engine performance that changes under load

Some vehicles may continue to operate almost normally when the ECM can compensate for the fault.

Other vehicles may immediately limit engine torque or turbocharger operation.

Can P0247 Cause Low Boost?

Yes.

If the wastegate solenoid cannot properly control the actuator, the wastegate may not move to the required position.

Depending on the system, this can result in the turbocharger producing less boost than requested.

The driver may notice:

• Sluggish acceleration

• Reduced torque

• Poor performance during overtaking

• Slow response when the turbocharger should build boost

• Limp mode

However, P0247 is fundamentally a circuit malfunction code. Low boost can also be caused by many other problems, such as an intake leak, boost leak, actuator problem or turbocharger fault.

Can P0247 Cause Overboost?

It can contribute to an overboost condition on some systems.

If the wastegate cannot open when required, exhaust gas may continue driving the turbocharger harder than intended.

This can result in excessive boost.

The ECM may then store additional turbocharger or boost-pressure codes.

If the vehicle is experiencing obvious overboost, repeated hard acceleration should be avoided until the problem has been diagnosed.

Common Causes of P0247

Faulty wastegate solenoid “B”

The solenoid itself can fail electrically or mechanically.

Possible problems include an internal coil fault, abnormal resistance, sticking, or failure to respond to the ECM's commands.

Damaged wiring

Turbocharger wiring operates in a high-temperature and high-vibration environment.

The harness can suffer from:

• Melted insulation

• Chafing

• Broken wires

• Short circuits

• Poor previous repairs

• Heat damage

• Engine-movement damage

Corroded connector

Water, oil, dirt and heat can damage the electrical connector.

Even slight corrosion or poor terminal tension can increase resistance or interrupt the circuit.

Open circuit

A broken wire or disconnected connector can prevent the ECM from controlling the solenoid.

Depending on the system, this can produce P0247 and potentially additional electrical codes.

Short to ground

If the control wire contacts a ground path, the circuit can behave differently from what the ECM expects.

This may also produce a more specific low-circuit code such as P0249.

Short to power

A control wire contacting an unintended voltage source can also disrupt solenoid operation.

Power supply problem

Some boost-control solenoids receive their power through a shared fuse or relay.

A problem in the shared power supply can therefore affect the solenoid without the solenoid itself being defective.

Vacuum or pressure-control problem

On systems that use pneumatic wastegate control, a damaged vacuum hose, leaking pressure line or restricted passage can prevent the actuator from responding correctly.

This may coexist with an electrical fault or create similar symptoms.

Sticking wastegate

Carbon deposits, corrosion, heat damage or mechanical wear can cause the wastegate mechanism to stick.

A sticking wastegate is a mechanical problem, whereas P0247 is an electrical circuit code, so both sides should be evaluated separately.

Faulty wastegate actuator

The actuator may have a damaged diaphragm, linkage problem, position-sensor issue or internal mechanical fault depending on the design.

ECM/PCM fault

The ECM provides the control signal and monitors the solenoid.

A failed output driver is possible, but it should generally be considered only after the wiring, connector, power supply and solenoid have been tested.

How Is P0247 Diagnosed?

A proper diagnosis should determine whether the problem is electrical, pneumatic, mechanical, or a combination of these.

1. Scan all DTCs

Do not diagnose P0247 by itself.

Look for additional codes related to:

• Boost pressure

• MAP sensor

• Turbocharger actuator

• Wastegate position

• Intake pressure

• Engine performance

• Other boost-control solenoids

• ECM power supply

Related codes can significantly narrow the diagnostic path.

2. Check freeze-frame data

Determine the conditions under which P0247 was recorded.

Useful information can include:

• Engine RPM

• Engine load

• Boost pressure

• MAP pressure

• Throttle position

• Engine temperature

• Vehicle speed

• Battery voltage

A fault that occurs only under heavy acceleration may require a different diagnostic approach from one that occurs immediately after starting.

3. Identify Wastegate Solenoid “B”

Confirm which physical component and circuit the manufacturer calls Solenoid “B.”

Do not rely solely on the generic OBD-II description.

4. Inspect the connector

Check for:

• Corrosion

• Bent pins

• Loose terminals

• Poor terminal tension

• Water intrusion

• Oil contamination

• Heat damage

• Broken locking tabs

The connector should be inspected carefully because it is often located in a hot and highly vibrating area.

5. Inspect the wiring

Trace the harness from the solenoid toward the ECM and power supply.

Look for:

• Broken conductors

• Chafing

• Melted insulation

• Short circuits

• Incorrect splices

• Previous repairs

• Wiring touching hot turbocharger components

A continuity test can be useful, but an intermittent fault may require testing while moving the harness or when the system is hot.

6. Check power and control circuits

Verify the electrical supply and control signal according to the manufacturer's wiring diagram.

Different vehicles use different strategies.

For example, one system may provide switched power to the solenoid and have the ECM control the ground side, while another system may use a different arrangement.

Because of these differences, universal voltage values should not be assumed.

7. Test the solenoid

Depending on the system, testing can include:

• Coil resistance

• Current draw

• Actuation test

• Electrical waveform

• Commanded activation

• Mechanical response

A solenoid that has acceptable resistance is not automatically proven good. It may still stick or fail when exposed to engine heat.

8. Check vacuum or pressure lines

If the wastegate system uses pneumatic control, inspect the associated hoses and passages.

Look for:

• Cracked hoses

• Disconnected hoses

• Leaks

• Restrictions

• Incorrect routing

A leak in the actuator-control system can prevent proper wastegate operation.

9. Check wastegate movement

The wastegate and actuator should move according to the manufacturer's specifications.

A mechanically stuck linkage can cause boost-control problems even when the electrical circuit is working correctly.

10. Compare commanded and actual boost

Use live scan-tool data to compare the boost pressure requested by the ECM with the actual pressure measured by the vehicle.

A consistent mismatch can point toward a problem with:

• Wastegate control

• Actuator

• Turbocharger

• Intake system

• Boost-pressure sensor

• Control strategy

11. Test the ECM last

The ECM should be considered only after the external circuit has been verified.

Before replacing an ECM, confirm:

• Correct power supply

• Correct grounds

• Correct wiring

• Good connectors

• Functional solenoid

• Correct control circuit behavior

P0247 vs P0248

These codes concern the same general wastegate solenoid “B” system but describe different problems.

P0247 – Circuit Malfunction

The ECM detects an abnormal electrical condition or malfunction in the circuit.

P0248 – Range/Performance

The ECM detects that the solenoid's operation is outside the expected range or performance.

P0248 can therefore be associated with a situation where the control system is electrically present but the resulting operation does not match what the ECM expects.

P0247 vs P0249

This is an especially useful comparison.

P0247 – Wastegate Solenoid “B” Circuit Malfunction

A general circuit malfunction has been detected.

P0249 – Wastegate Solenoid “B” Circuit Low

The ECM specifically detects a low electrical condition.

P0249 therefore provides more specific information about the electrical state than P0247.

P0247 vs P0246

P0246 concerns Turbocharger/Supercharger Wastegate Solenoid “B” Circuit High.

P0247 is the broader circuit malfunction description.

P0246 points toward an abnormally high electrical condition, while P0247 does not specify whether the electrical problem is high, low, open, intermittent or another type of malfunction.

P0247 vs P0243

P0243 concerns Turbocharger/Supercharger Wastegate Solenoid “A” Circuit Malfunction.

P0247 concerns Solenoid “B” Circuit Malfunction.

The important distinction is the circuit designation. The exact physical locations of “A” and “B” are manufacturer-dependent.

Is P0247 an Electrical or Mechanical Code?

Primarily, P0247 is an electrical circuit code.

However, the electrical control system operates a mechanical or pneumatic boost-control mechanism.

This means a complete diagnosis may eventually need to evaluate both sides.

For example:

A faulty solenoid → electrical problem → incorrect wastegate operation → low boost.

But:

A sticking wastegate → mechanical problem → incorrect boost → possibly additional boost-performance codes.

These situations should not be treated as identical.

Can a Bad Turbocharger Cause P0247?

A defective turbocharger can cause symptoms associated with P0247, but the DTC alone does not prove that the turbocharger itself has failed.

Before replacing the turbocharger, inspect and test:

• Wastegate solenoid

• Electrical wiring

• Connector

• Power supply

• Control circuit

• Vacuum/pressure lines where applicable

• Wastegate actuator

• Wastegate linkage

A relatively inexpensive electrical fault can otherwise lead to an unnecessary turbocharger replacement.

Can You Drive With P0247?

If the vehicle has only a Check Engine Light and continues to operate normally, a short drive to a repair facility may be possible.

However, the vehicle should not be repeatedly driven hard if it has:

• Severe power loss

• Sudden boost changes

• Limp mode

• Excessive smoke

• Unusual turbocharger noises

• Severe hesitation

• Possible overboost

• Unstable engine operation

A malfunctioning wastegate-control system can make boost behavior unpredictable.

Does P0247 Need Immediate Repair?

The urgency depends on the symptoms.

A vehicle that drives normally may not require immediate roadside recovery, but the problem should still be diagnosed rather than ignored.

If there is significant power loss or suspected overboost, avoid heavy acceleration until the cause is established.

What Is the Correct Repair for P0247?

The correct repair depends on the actual fault found during testing.

Possible repairs include:

• Replacing Wastegate Solenoid “B”

• Repairing damaged wiring

• Replacing damaged terminals

• Repairing an open circuit

• Repairing a short circuit

• Correcting a power-supply problem

• Repairing vacuum or pressure lines

• Replacing a faulty wastegate actuator

• Repairing a sticking wastegate

• Correcting a boost-control problem

• Repairing an ECM control circuit

• Replacing the ECM in rare cases

After the repair, the code should be cleared and the vehicle tested under the conditions that originally triggered P0247.

A Practical Diagnostic Sequence

A logical approach is:

P0247 → identify Solenoid “B” → inspect connector → inspect wiring → verify power and control circuit → test solenoid → check vacuum/pressure system → inspect actuator and wastegate → compare commanded and actual boost → evaluate ECM last.

This prevents the common mistake of replacing the turbocharger before checking the relatively simple electrical components that actually control it.

Final Diagnosis

P0247 – Turbocharger / Supercharger Wastegate Solenoid “B” Circuit Malfunction means that the ECM/PCM has detected an abnormal condition in the electrical circuit controlling wastegate solenoid “B.”

The code does not automatically mean that the turbocharger is defective, nor does it specifically indicate low or high boost pressure.

The fault can be caused by a failed solenoid, damaged wiring, poor connector contact, open or shorted circuit, power-supply problem, actuator issue, vacuum/pressure problem, or, less commonly, an ECM fault.

The most reliable diagnosis is to identify the exact “B” circuit for the vehicle, verify its electrical supply and control signal, test the solenoid, and then evaluate the actuator and mechanical wastegate system. This approach makes it possible to distinguish a simple electrical fault from a genuine turbocharger or wastegate problem.