P2403
P2403Diagnosis information - DME V6 DFI
Reed switch for leakage diagnosis pump
Diagnostic conditions
- Short tank leakage test + short test tank vent valve within one engine operating period
or:
- Vehicle voltage 9 V ... 16 V
- Ambient air pressure > 730 hpa (below approx.2400... 2700 m above sea level)
- The engine must have cooled down by at least 42 °C (76 °F) between when it was last switched off and restarted
- Engine temperature > 5 °C (41 °F)
- Intake air temperature > 5 °C (41 °F)
- Fluctuations in the intake air temperature of less than 12 °C (21 °F)
- Drive with long partial load portion
- Vehicle speed 3 ... 150 km/h (2... 93 mph)
Possible fault causes
- Vacuum system leaking
--> The system consists of the mechanical vacuum pump (on the vehicle engine), the brake booster, etc., the leakage diagnosis pump, the intake pipe switch-over valve and, where appropriate, the exhaust flaps in the rear muffler
- Vacuum pump faulty
- Reed switch in leakage diagnosis pump faulty
Affected contacts on the DFI control unit connector
Connector [B]:
- Contact 40
NOTE:
The tank leakage test can be performed on the Cayenne wit a tank pressure of approx. 20 mbar. This pressure is built up by the leakage diagnosis pump and evaluated by an integrated reed contact. The pump work is done by a spring put under tension by a vacuum from the intake pipe (or supply tank) via a diaphragm.
The diagnostic conditions can also be enforced using the PIWIS Tester via the short test >leakage diagnosis<.
The reed switch in the leakage diagnosis pump is checked before the actual tank leakage test. If, after the test has been begun (application of vacuum to leakage diagnosis pump), it is in an implausible position (here: closed), a fault is entered and the tank leakage test is terminated.