Kessy/Immobiliser
Fault code 0576Terminal 15 (diagnosis of feedback signal lead)
Diagnostic conditions
- Internal KESSY control module function test
- Ignition off
Possible cause of fault
- Short circuit to B+
- Short circuit to ground or open circuit in wiring
- Fuse F39 (5A) in fuse carrier at left of dashboard faulty
- Relay for terminal 15 faulty
- Control unit faulty
NOTE: In the event of a short circuit to B+ on the line between control module plug A, pin 14 and the relay for terminal 15, pin 5, a signal indicating that the ignition is still on is sent to the control module when an attempt is made to switch off the ignition on this line. Result: If the short circuit to B+ is still 'static', the ignition can no longer be switched on because the control module assumes that it is already switched on.
Affected pins
- Plug A on control module: Pin 14
- Relay for terminal 15 in current distributor (under left seat; relay no. 433): Pin 5
Diagnosis/troubleshooting
NOTE:
Visual inspection: In the next troubleshooting section, please check first that the affected pins on the KESSY control module plug connection are neither damaged nor corroded. The wiring and plugs of the affected components must also be checked for external damage and correct contacts. Repair damaged or corroded pins if possible, otherwise replace affected pins. Repair or replace damaged wires.
NOTE:
Sporadic faults: In the event of faults that occur sporadically, the wiring positions that are linked to moving parts on and in the vehicle must be checked for each system. Various statuses that can cause faults must be simulated with the help of the wiring diagram.
NOTE: Conventional diagnosis/troubleshooting cannot be performed for the fault type 'short circuit to B+', which is displayed using the 'F8' key in the 9588 Porsche System Tester II. The reason for this is that the ignition cannot be switched on when there is no control module connected. As a result, it is not possible to differentiate uniquely between a short circuit to terminal 30 and a short circuit to terminal 15. A thorough visual inspection of components and wiring must therefore be carried out before replacing a control module.
