Charge Pressure Upper Limit Exceeded
1997-2000 BMW 528i E39 2.8L I6 🇬🇧
Description
The DME detected that the turbocharger boost pressure has exceeded the maximum allowed limit. This is an overboost condition that can cause severe engine damage if not addressed immediately.
Symptoms
- Check Engine Light
- Reduced power mode
- Overboost felt as sudden power surge
- Engine may shut down
- Possible engine knock
Common Causes
- Wastegate stuck closed
- Boost control solenoid failure
- Wastegate actuator diaphragm leak
- Charge pipe leak causing incorrect sensor reading
- Boost pressure sensor fault
Diagnostic Steps
- Monitor actual vs target boost pressure
- Test wastegate operation manually
- Check boost control solenoid
- Inspect charge pipes for leaks
- Test boost pressure sensor accuracy
Repair Notes
Immediately repair the overboost condition to prevent engine damage; check wastegate and boost control solenoid.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1555 on Other Vehicles
Common Questions
What does code P1555 mean on a 1997-2000 BMW 528i E39?
P1555 stands for "Charge Pressure Upper Limit Exceeded". The DME detected that the turbocharger boost pressure has exceeded the maximum allowed limit. This is an overboost condition that can cause severe engine damage if not addressed immediately.
What are the symptoms of P1555 on a BMW 528i E39?
Common symptoms of P1555 include: Check Engine Light, Reduced power mode, Overboost felt as sudden power surge, Engine may shut down, Possible engine knock.
What causes P1555 on a 1997-2000 BMW 528i E39?
Common causes of P1555 include: Wastegate stuck closed, Boost control solenoid failure, Wastegate actuator diaphragm leak, Charge pipe leak causing incorrect sensor reading, Boost pressure sensor fault.