Turbocharger Wastegate Solenoid B Low
Code P0249 indicates the PCM detected a low voltage condition in the wastegate/boost pressure control solenoid B circuit. This solenoid regulates turbo boost pressure, and a fault prevents proper boost management, reducing engine power and performance.
What You Might Notice
- Malfunction Indicator Light (MIL) illuminated on dashboard
- Loss of engine power or reduced acceleration
- Instrument cluster warning message displayed
- Turbocharger boost pressure not building properly
- Rough idle or hesitation under load
Most Common Causes
- 1
Open ground circuit connection
A break or loose connection in the ground circuit between the wastegate solenoid B and the PCM prevents proper current flow, causing low voltage detection.
- 2
Open power supply circuit
A broken wire or disconnected connector in the power supply line to the solenoid prevents adequate voltage from reaching the component.
- 3
Faulty wastegate control solenoid B
The solenoid itself may have internal winding damage or electrical failure, causing it to draw excessive current or fail to operate properly.
- 4
Short to ground in solenoid circuit
A damaged wire or connector causing an unintended ground connection reduces voltage available to the solenoid, triggering the low voltage code.
How to Diagnose It
- 1
Check Open ground circuit connection — A break or loose connection in the ground circuit between the wastegate solenoid B and the PCM prevents proper current flow, causing low voltage detection.
- 2
Check Open power supply circuit — A broken wire or disconnected connector in the power supply line to the solenoid prevents adequate voltage from reaching the component.
- 3
Check Faulty wastegate control solenoid B — The solenoid itself may have internal winding damage or electrical failure, causing it to draw excessive current or fail to operate properly.
- 4
Check Short to ground in solenoid circuit — A damaged wire or connector causing an unintended ground connection reduces voltage available to the solenoid, triggering the low voltage code.
How to Fix It
- 1
Inspect and repair wiring harness
Visually inspect the wiring and connectors between the wastegate solenoid B and PCM for corrosion, loose connections, or damaged insulation. Repair or replace damaged wiring and reseat all connectors securely.
- 2
Test and replace solenoid connector
Check the connector pins at the solenoid for corrosion or poor contact. Clean contacts with electrical contact cleaner or replace the connector assembly if damaged.
- 3
Replace wastegate control solenoid B
If wiring and connections test good, replace the solenoid with a new OEM or equivalent unit. Verify correct solenoid type for your specific turbocharger system.
- 4
Perform PCM diagnostics
If all external circuits and solenoid check good, have the PCM tested by a specialist, as internal PCM failure is rare but possible. Consider PCM reprogramming or replacement only after all other causes are ruled out.
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