LL calibration (NG engines)

In the various operating states, the engine management system specifies a certain idle speed (e.g. running at operating temperature). For some of these operating states, this service function can be used to set the idle speed.

Preconditions

For the adjustment, the conditions specified in the test module must be met. Otherwise the engine management system could detect another operating state which, under certain circumstances, does not permit adjustment or sets another idle speed.

Range of adjustment

The range of adjustment is limited and dependent on the engine model and software version of the engine management system.

The adjustment input must be rounded up or down to the nearest ten. Example: An adjustment of 755 rpm is not possible; instead, 750 or 760 rpm must be entered.

Operating states for which an adjustment is possible

• without engine-speed increase (Block 1)
  
  • Base state State that is not influenced by additional loads or states such as running at operating temperature or fault entries.
    
  • Drive position on
    

• with engine-speed increase (Block 2)
  
  • Air-conditioning compressor on State in which the air conditioning system is switched on and the air-conditioning compressor works
    
  • Air-conditioning compressor and drive position on
    
  • low battery voltage This operating condition is not always directly recognisable and can also occur with the correct on-board supply voltage and the engine running
    

Note

• Causes of problems with the adjustment can be operating states that are without easily recognisable, such as low battery voltage or fault detection
  
• If a uniform idle speed is desired, both blocks must be set the same.