• U0129

  U0129

  
  

  Diagnosis information - CAN PSM control unit, communication Diagnostic conditions

  The PSM 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.
  PSM control unit wake-up through:
  
  
• Event-induced CAN message
• Ignition on
  
  

  Possible fault causes

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

  Affected contacts on the PSM control unit

  
  
  Connector [A]:
• 1 power supply - terminal 30
• 4 power supply - terminal 15
• 6 power supply - terminal 30
• 11 CAN drive high
• 15 CAN drive low
• 16 ground supply - terminal 31
• 32 power supply - terminal 30
• 47 ground supply - terminal 31