Fault code 2042: Diagnosis/troubleshooting

NOTE: Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

NOTE: Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control unit. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Work instruction			Display OK	If not OK
1	Check open circuit:	Measurement '1a': Ignition off Pull plug 'A' off servo motor Measure resistance (servo motor winding) between 'pins A1 and A4' of servo motor plug 'A'.	0.8 Ω go to measurement '1b'	If ∞ Ω then: Go to Step 2
1	Check open circuit:	Measurement Pull plug off transfer box control unit Measure resistance between 'pins 15, 16' of transfer box control unit plug and 'pins A1, A4' of removed lock plug 'A'.	< 5 Ω Go to Step 3	Repair wiring harness to servo motor. → End
2	Replace transfer box servo motor		→ End
3	Replace transfer box control unit		See note on replacing control units! → End