P2403
EVAP System Leak Detection Pump Sense Circuit Open
The leak detection pump (LDP) - which actively pressurises the EVAP system to find leaks - has an open sense circuit. The ECU cannot read the pump status during the diagnostic cycle.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Common causes
Ordered by how often each turns out to be the cause.
- Open in pump or sense wiringCommon
- Pin pushed back out of connector bodyLess likely
- Cracked solder joint inside the module or sensorLess likely
Parts involved
- EVAP Leak Detection Pump
P2403 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.