P2403
P2403Evaporative Emission System Leak Detection Pump Sense Circuit/Open
Diagnostic conditions
- Battery positive voltage between 10 V and 16 V
- Engine must cool down by at least 42 K in the time that elapses between stopping and restarting engine
- Intake air temperature between 5 °C and 95 °C
- Variations of intake air temperature less than 12 K
- Vehicle is travelling with longer partial load share (3 - 150 km/h)
- Engine temperature higher than 5 °C
- Diagnosis only runs below 2,400 m above sea level
- No P0441, P0444, P0445 (Evaporative Emission System Purge Control Valve Circuit Shorted) or P0446, P0447, P0448 (Evaporative Emission System Vent Control Circuit Shorted) faults in memory
- No P0455 (Evaporative Emission System Leak Detected (large leak)) in memory
- No P2400, P2401, P2402 (Evaporative Emission System Leak Detection Pump Control Circuit High) fault in memory
Possible cause of fault
- EVAP canister purge valve stuck in closed position
- Purge air line between EVAP canister purge valve and active charcoal filter blocked
- Open circuit in signal line
- Short circuit to ground in signal line
- Leakage diagnosis pump faulty (diaphragm or reed switch stuck, solenoid valve stays open)
- DME control module faulty
Affected terminals
Connector A, pin 80
Diagnosis/troubleshooting
NOTE:
- The fuel tank leak test for the Cayenne is carried out with approx. 20 mbar overpressure in the tank. This overpressure is built up by the leakage diagnosis pump and is evaluated using an integrated reed contact. The pump work is performed by a spring, which is stretched via a diaphragm by the vacuum from the intake manifold (or supply tank).
- The diagnostic conditions can also be 'forced' by performing the "Leakage Diagnosis" short test using the 9588 Porsche System Tester II.
- The reed switch in the leakage diagnosis pump is checked before the actual tank leak test is performed. If, at the beginning of the test, the reed switch is in an implausible position (in this case: open) even after activation of the EVAP canister purge valve, the fault is entered and the tank leak test is aborted.
DANGER:
- If this fault is detected in a vehicle, it is possible that the fuel tank and ventilation system are under pressure.
- Therefore, before starting to work on the tank system, carefully relieve the overpressure by opening the tank cap slowly.
DANGER:
- Danger of poisoning through petrol.
- Inhaling vapours can lead to irritation of the mucous membranes and eyes.
- It represents a serious risk to health when inhaled, touched or swallowed over longer periods.
- Wear a breathing mask with active charcoal filter; do not breathe in any fuel vapours.
- Wear protective gloves that are fuel resistant.
- Only work on the fuel system in well-ventilated locations.
- Before opening fuel lines or fuel hoses, relieve the fuel pressure.
- Collect escaping fuel; absorb it if necessary with a suitable binding material and dispose of properly
- Pay attention to cleanliness when working on the fuel system.
DANGER:
- Risk of tire and explosion when handling petrol.
- Keep clear of ignition sources.
- Do not smoke.
- Do not carry out welding or grinding work in the immediate vicinity (naked flame and flying sparks).
- Prevent escaping fuel from coming into contact with hot engine components.
- Avoid electric discharges in the vicinity of escaped fuel.
- Secure the vehicle, e.g. with a warning sign.
- Change any clothing soaked with fuel immediately.
- In the event of a fire, use C02 or dry powder fire extinguishers.
1 - Vacuum line disconnection point between vacuum accumulator in intake manifold and leakage diagnosis pump
2 - Purge air line disconnection point between active charcoal filter and EVAP canister purge valve
3 - Fuel supply line disconnection point
9160/1 Mityvac II vacuum tester with pressure gauge
Evaporative Emission System Leak Detection Pump Sense Circuit/Open
