P043FEVAP System Leak Detection Reference Orifice High Flow
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The evaporative emission (EVAP) system stores fuel vapour from the tank in a charcoal canister; a purge valve lets the engine draw it off, and a vent valve opens the canister to fresh air. Systems with a leak detection pump (Bosch DM-TL at VW, Audi, BMW and Maserati, Denso's canister pump module at Toyota/Lexus) first measure a reference value with the pump working only through a built-in 0.5 mm (0.020 in) orifice; it is the yardstick for the small-leak test that CARB requires. P043F means the reference measurement shows too much flow – the reference vacuum or pressure does not reach the expected value, because the reference path or changeover valve leaks, the pump is weak, or air enters through leaking valves in the test path. The leak test can then not be judged, since a weak yardstick would hide leaks. GM and Ford do not use the code.
- What you may notice
- Check engine light on
- EVAP leak test does not run, readiness not set
- Usually no change in driving
- Likely causes
- LikelyLeak detection pump faulty (weak pump, leaking changeover valve, liquid damage)
- PossiblePurge valve does not seal
- PossiblePump supply or connector (contact resistance, corrosion)
- RareLeaking hose between pump module and canister
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.