What does code P1128 mean?

Q: What does code P1128 mean?

Long Term Fuel Trim Bank 1 System Too Lean. P1128 on a Volkswagen means the engine computer has detected that the long-term fuel trim on bank 1 has reached its lean correction limit, so the engine is running with too much air or not enough fuel. The computer has been adding fuel beyond its normal adaptive range for an extended period and has now flagged the mixture as uncorrectable within its programmed limits.

DTC codes / Volkswagen codes / P1128

P1128 · VolkswagenLong Term Fuel Trim Bank 1 System Too Lean

P1128 on a Volkswagen means the engine computer has detected that the long-term fuel trim on bank 1 has reached its lean correction limit, so the engine is running with too much air or not enough fuel. The computer has been adding fuel beyond its normal adaptive range for an extended period and has now flagged the mixture as uncorrectable within its programmed limits.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.