Long Term Fuel Trim System Too Rich Bank 1
2002-2005 Audi A4 3.0L V6 🇩🇪
Description
The ECU detected that the long-term fuel trim for Bank 1 has exceeded the maximum rich correction limit. The engine is consistently receiving too much fuel and the adaptive system cannot compensate further.
Symptoms
- Check Engine Light
- Rich exhaust odor
- Black exhaust smoke
- Poor fuel economy
- Rough idle
Common Causes
- Leaking fuel injectors
- Faulty fuel pressure regulator (excess pressure)
- O2 sensor reading false lean
- EVAP purge valve stuck open
- Coolant temperature sensor reading colder than actual
Diagnostic Steps
- Monitor long-term and short-term fuel trims
- Test O2 sensor response time
- Check fuel pressure with gauge
- Inspect EVAP purge valve
- Test coolant temperature sensor
Repair Notes
Identify and repair the root cause of excess fuel delivery on Bank 1.
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
P1127 on Other Vehicles
Common Questions
What does code P1127 mean on a 2002-2005 Audi A4?
P1127 stands for "Long Term Fuel Trim System Too Rich Bank 1". The ECU detected that the long-term fuel trim for Bank 1 has exceeded the maximum rich correction limit. The engine is consistently receiving too much fuel and the adaptive system cannot compensate further.
What are the symptoms of P1127 on a Audi A4?
Common symptoms of P1127 include: Check Engine Light, Rich exhaust odor, Black exhaust smoke, Poor fuel economy, Rough idle.
What causes P1127 on a 2002-2005 Audi A4?
Common causes of P1127 include: Leaking fuel injectors, Faulty fuel pressure regulator (excess pressure), O2 sensor reading false lean, EVAP purge valve stuck open, Coolant temperature sensor reading colder than actual.