P043E code meaning
EVAP System Leak Detection Reference Orifice Low Flow
Powertrain system Generic code P04xx codes Check engine light
What P043E means
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.
P043E at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P043E
- Check engine light on
- EVAP leak test does not run, readiness not set
- Usually no change in driving
Common causes of P043E
- Most 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)
- Less likelyEngine module software (false detection)
- Less likelyPump connector or supply (voltage dip)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EVAP leak detection pumpReference orificeCharcoal canisterEngine control module
What each part of P043E means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 3E | The exact fault in that area. |
What to do next
- Note P043E and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P043E
What does P043E mean?
P043E means "EVAP System Leak Detection Reference Orifice Low Flow". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P043E?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P043E fail an emissions test?
Yes, it can. P043E is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P043E to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P043E clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.