Code Definition

P1127 — Fuel mixture RICH, long term fuel trim

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: Hyundai

About P1127

P1127 is a manufacturer-specific powertrain diagnostic trouble code recorded for Hyundai vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

P1127 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The Powertrain Control Module (PCM) trims fuel delivery from oxygen sensor feedback using both an additive correction at idle and a multiplicative correction across the higher load and speed range. DTC P1127 is set on Hyundai and Kia vehicles when the long term multiplicative fuel trim for Bank 1 reaches its maximum negative (subtract fuel) limit under moderate to high engine load because the air fuel mixture is persistently rich. Unlike the idle rich code P1123, this fault is detected away from idle, so it points more strongly at conditions that richen the mixture as airflow and load increase...

Join TaT to view the complete code information and diagnostic details.

Quick Facts