Start of Injection Closed-Loop Control DDE 3.0

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Function

The setpoint for start of injection control is derived from following variables for the operating status:

• Engine speed
  
• Injection quantity
  
• Coolant temperature
  
• Atmospheric pressure
  
• Boost pressure
  
• Fuel temperature
  

The start of injection is set in the injection pump by means of the timing valve for the injection timing device. The needle movement sensor at cylinder No. 4 signals the actual start of injection back to the DDE control unit. The DDE control unit controls the timing valve of the injection timing device such that the difference between the setpoint and actual start of injection is as low as possible. Fault code 0A "start of injection closed-loop control" is stored if the difference is too great (tolerance depending on operating status approx. +/-2° crank angle). In addition, the position control of the injection timing device is also monitored and fault code 48 "injection timing device control" is stored in the case of fault.

Troubleshooting

If fault code 0A or 48 is stored, the injection rate is limited to 25 mg/stroke.

In this case, the system changes over from start of injection closed-loop control to start of injection open-loop control with fixed duty factor in case of:

• Fault code 0A, "start of injection closed-loop control"
  
• Fault code 2F, "crankshaft position/rpm sensor"
  
• Fault code 47, "synchronism of rpm sensors"
  
• Fault code 10, "supply voltage"
  
• Fault code 5, "needle movement sensor"
  
• Starting the engine
  
• Deceleration fuel cutout