What it means
Same as P054E with actual fuel quantity above the model - high friction, sticky throttle, or accessory drag.
At a glance
- Usually lights the check-engine light
How it works
At idle, the control module estimates the fuel needed to hold the target engine speed. P054F sets when the calculated fuel quantity is higher than expected, which can accompany excessive idle-air demand or an inaccurate airflow, fuel, or engine-load signal.
Common causes
Most likely first.
- Excessive or unstable idle air demand
- Air leak or incorrect airflow measurement
- Fuel delivery or mixture-control problem
- Incorrect engine load or sensor input
Symptoms
- Check-engine light on
- Rough or unstable idle
- Higher-than-normal idle speed or possible stalling
How to diagnose it
- Read freeze-frame data and live idle values for engine speed, airflow, fuel trims, and calculated load to identify when the excess fuel estimate appears.
- Check whether idle speed is higher than normal and inspect the throttle area and intake for sticking or unintended airflow.
- Inspect intake hoses and vacuum connections for leaks that could make measured airflow differ from actual airflow.
- Compare airflow and engine-load sensor readings at idle with the manufacturer's specifications.
- Check fuel-delivery and mixture-control data against the manufacturer's specification if the air and load readings appear plausible.
- Test idle-control components and related sensor inputs if the cause is not apparent from the basic checks.
Common fixes
- Repair a leaking intake hose or vacuum connection.
- Clean or repair a sticking throttle or idle-air control component.
- Repair an airflow sensor or engine-load sensor that reports inaccurate values.
- Correct a fuel-delivery or mixture-control fault found during testing.
- Repair an accessory or load input that is causing an incorrect idle demand calculation.
Can I keep driving?
If the engine remains controllable, drive gently and avoid relying on a stable idle in traffic or during maneuvers. Have it checked promptly if idle speed rises, becomes erratic, or the engine stalls.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.