P1556
Charge Pressure Negative Deviation
Severity
⚠️ MediumCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–167 (est.)
Symptoms
- Reduced engine power
- Increased fuel consumption
- Unstable idling
- Slow throttle response
- Noise or whistle from the engine compartment
Causes
- Air leak in the intake tract
- Turbocharger malfunction
- Bypass valve clogged or faulty
- Problems with vacuum hoses or solenoids
- Boost pressure sensor malfunction
How to Fix
- Check the tightness of the intake tract
- Diagnose the operation of the turbocharger
- Check the condition of the bypass valve
- Inspect vacuum hoses and connections
- Check boost pressure sensor