Porsche Diagnostic and Repair Information ,Wiring Diagrams. DTC. TSB. Types: TSB, DTC, Wiring Diagrams, OEM Procedures. Trusted by more than 400,000 technicians. OEM accurate fix for faster repairs. Repair Procedures and Labor Times. Factory Auto Repair info. Request A Demo Today. Factory-Correct Diagrams. Factory Part Numbers. Maintenance Schedules. Repair Procedures. Labor Times. Types: TSB, DTC.car insurance, auto insurance, auto, car, vehicle, insurance, quote, quotes, online, insurance，auto, autos, car, cars, vehicle, vehicles, used car, pre-owned car, pre-owned vehicle, used auto, used vehicle, rental，auto racing news, car racing news

• P1621

  P1621

  
  

  Diagnosis information - CAN Communication, Tiptronic control unit Diagnostic conditions

  The Tiptronic control unit initially tests internal function sequences after wake-up. If they are OK, all diagnosable outputs are then tested and any faults are stored.
  Tiptronic control unit wake-up through:
  
  
• Event-induced CAN message
• Ignition on
  
  

  Possible fault causes

• No power supply for Tiptronic control unit
• Tiptronic control unit is incorrectly coded
• Short circuit or open circuit in the CAN drive
• Tiptronic control unit faulty (in most cases the cause is not the Tiptronic control unit but incorrect coding.)
  
  

  Fault effects

• Communication via the CAN drive is no longer possible
• No other control units are able to communicate with the Tiptronic control unit
  
  

  Affected contacts on the Tiptronic control unit

  
  
  Connector [A]:
• 1 ground supply - terminal 31
• 2 ground supply - terminal 31
• 3 power supply - terminal 30
• 27 power supply - terminal 15
• 28 power supply - terminal 15
• 34 CAN drive low
• 46 CAN drive high