Fault Code 0166

Fault Code 0166

Electronic ignition starting switch

Diagnostic conditions
- Internal KESSY control module function test

Possible cause of fault
- No signal/communication (no communication between control module and ignition starting switch)
- Electrical fault in electric circuit (plug contact problem)
- Short circuit to ground or open circuit in wiring
- Short circuit to B+ or open circuit in wiring
- Short circuit to ground
- Short circuit to B+
- Open circuit in wiring
- Electronic ignition starting switch faulty
- Control unit faulty

Affected pins
- Ignition switch plug: Pin 1, Pin 2, Pin 3, Pin 4, Pin 5, Pin 6, Pin 7, Pin 8, Pin 9, Pin 10, Pin 11, Pin 12
- Plug A on control module: Pin 19, Pin 33, Pin 35, Pin 37, Pin 40, Pin 41, Pin 52, Pin 53, Pin 55, Pin 57
- Plug B on control module: Pin 4, 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.
- Conventional diagnosis/troubleshooting cannot be performed for the fault type short circuit to B+, which is displayed using the F8 key in the Porsche System Tester II 9588. 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.
- The resistance values specified below are based on an ambient temperature of 20 degree C

Plug for ignition starting switch