What it means
During the EVAP leak-detection self-test, the calibration airflow through the reference orifice is below the expected rate. The orifice may be partially blocked.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The EVAP leak-detection system uses a calibrated reference orifice to check airflow during its self-test. P043E means the measured flow through that orifice is lower than expected, which can happen if the orifice or its passage is restricted or the pump cannot move air properly.
Common causes
Most likely first.
- Reference orifice partially blocked
- Dirt or debris in the leak-detection passage
- Fault in the leak-detection pump or airflow path
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
How to diagnose it
- Confirm P043E and review freeze-frame data and any related EVAP codes to identify the conditions of the failed self-test.
- Check that the fuel cap is correctly fitted and inspect accessible EVAP hoses and connections for kinks, blockage, or damage.
- Inspect the leak-detection assembly and its reference-orifice passage for dirt or debris, following the vehicle's service information.
- Use a scan tool's EVAP test, if available, to check whether the leak-detection pump runs and whether the system reports the expected airflow response.
- If the passage is clear, test the pump and airflow path using the manufacturer's procedure before replacing components.
Common fixes
- Refit or replace a damaged fuel cap.
- Clear debris from the reference-orifice passage using the vehicle's service procedure.
- Repair a kinked, blocked, or damaged leak-detection hose.
- Replace a faulty leak-detection pump if it fails the manufacturer's test.
Can I keep driving?
The code usually does not affect drivability, but the vehicle may fail an emissions inspection. If you smell fuel, check for a loose cap and avoid ignition sources near the vehicle; seek prompt attention if the smell persists or is strong.
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.