Fuel and air

P0249 — Turbo Wastegate Solenoid B Circuit Low or Performance Problem

Severity: medium Drive with care, to a shop

What P0249 means

The engine computer controls boost by using a solenoid to regulate the actuator on the turbo's wastegate. P0249 sets when the voltage in the solenoid B circuit is too low or the circuit does not perform as commanded. The computer then cannot regulate boost accurately.

Symptoms

  • Check Engine light on
  • Sluggish acceleration and reduced power
  • Boost pressure lower than normal under load
  • Possibly worse fuel economy
  • Possible limp mode with limited power
  • Occasional unusual turbo noise

Possible causes

  1. Failed wastegate control solenoid B
  2. Damaged wiring or poor connection in the solenoid circuit
  3. Wiring shorted to ground
  4. Faulty output driver in the ECM/PCM
  5. Vacuum line leaks or actuator linkage problems
  6. Sticking or faulty wastegate actuator

How to diagnose

  1. Read codes and freeze frame data and look for other boost-related codes
  2. Inspect the solenoid wiring and connector for chafing, melting, corrosion and oil contamination
  3. Measure the solenoid coil resistance and compare it with the factory spec
  4. Test the power and control wires for opens and shorts to ground
  5. Inspect vacuum hoses and lines for cracks, kinks and leaks
  6. Command the solenoid with a scan tool and confirm the actuator moves through its full range
  7. Compare specified and actual boost in live data under load
  8. If the wiring and solenoid are good, check the control signal at the ECM output

Common fixes

  • Replace wastegate solenoid B
  • Repair the wiring or replace a damaged connector
  • Replace cracked vacuum hoses
  • Replace or adjust the wastegate actuator if it sticks
  • Reflash or replace the ECM/PCM if the driver fault is confirmed

Questions and answers

What does P0249 mean?

It means the ECM detected a low signal or poor performance in the wastegate solenoid B circuit. As a result it cannot precisely control turbo boost.

Can I drive with P0249?

Briefly and gently, to reach a shop, avoiding heavy loads. Extended driving with uncontrolled boost can damage the turbo and engine.

What most often causes P0249?

Most often it is a failed solenoid or damaged wiring and connectors. Less often the cause is vacuum lines, the actuator or the ECM.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.