P043EEVAP System Leak Detection Reference Orifice Low 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. P043E means the reference measurement shows too little flow – the vacuum (or with DM-TL the pressure and pump current) becomes stronger than expected, so the orifice or reference path is partly blocked, often by dirt or liquid after overfilling. GM and Ford do not use the code; Maserati fixed false triggering with software.
- What you may notice
- Check engine light on
- EVAP leak test does not run, readiness not set
- Usually no change in driving
- Likely causes
- LikelyReference orifice or pump module dirty or blocked by liquid (overfilled tank, splash water)
- PossibleLeak detection pump faulty (weak or blocking pump, changeover valve stuck)
- RareEngine module software (false detection)
- RarePump connector or supply (voltage dip)
- 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: €0 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.