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Home >> Porsche >> 2004 >> Cayenne Base >> Repair and Diagnosis >> Body & Frame >> Towing Systems >> Trailer Hitch >> Fault code 2579 >> Diagnosis/troubleshooting

Fault code 2579: Diagnosis/troubleshooting

NOTE:
  • When troubleshooting, the status of the fault must be observed!
  • Use a suitable test cable or a trailer (which is definitely OK) to check whether the fault is present on the vehicle or whether it is reoccurring.
  • A short circuit to B+ can also be a short circuit to supply leads of other loads. The leads must be supplied with power for test purposes.
DIAGNOSIS/TROUBLESHOOTING PROCEDURE

Work instruction Display OK If not OK
1 Connect test cable (tool) or OK trailer to trailer socket and check whether functions are present or whether the fault occurs again Fault does not occur again.
Fault exists in trailer; repair bulb/light, plug connector or wiring.
→ End
Fault is still present.
Go to Step 2
2 Check fault memory in the trailer hitch control module for [F8] fault 'Open circuit'
'Short circuit to ground' Lamp is not lit
Go to Step 3
'Short circuit to B+' Light is lit continuously
Go to Step 4
3 Check wiring in vehicle between trailer hitch control module and trailer socket for an open circuit
  • Ignition off.
  • Switch off ignition.
  • Pull off plug A on trailer hitch control module.
  • Measure resistance between pin 7 of plug A on trailer hitch control module and pin 1 of trailer socket.
< 5 Ω
Go to Step 4
Repair wiring or replace wiring harness.
→ End
4 Check wiring in vehicle between trailer hitch control module and trailer socket for a short circuit to ground
  • Check resistance between trailer socket, pin 1, and ground.
∞ Ω
Go to Step 7
Repair wiring or replace wiring harness.
→ End
5 Check wiring in vehicle between trailer hitch control module and trailer socket for a short circuit to B+ (see note)
  • Push plug A on to trailer hitch control module.
  • Switch on ignition.
  • Check voltage between trailer socket, pin 1, and ground (brake not applied).
< 0.3 V
Go to Step 6
Repair wiring or replace wiring harness.
→ End
6 Check ground leads
  • Measure resistance between trailer socket, pin 2, and vehicle ground.
< 5 Ω
Go to Step 7
Repair wiring or replace wiring harness.
→ End
7 Replace trailer hitch control module → End