Crankshaft Position/RPM Sensor DDE 3.0

The inductive rpm sensor is installed on the engine block near the flywheel. Four pins are mounted on the flywheel which move past the rpm sensor at defined distance. The DDE control unit evaluates the resulting voltage signals for the purpose of calculating the engine speed.

The rpm sensor signal is used as a measurement variable for:

• Exhaust gas recirculation
  
• Checking start conditions
  
• Calculating start volume
  
• Start of injection control
  
• Checking switch-on conditions for air conditioning system
  
• Calculating limitation volume
  
• Calculating external delivery rate intervention
  
• Boost pressure control
  
• Injection rate control
  
• Idle speed control
  

Troubleshooting

The following types of fault are monitored:

• Overspeed recognition
  
• Implausible change in engine speed
  
• Plausibility with injection pump speed/rpm sensor
  

Fault code 2F "crankshaft position/rpm sensor" is stored if the rpm sensor is defective. Fault code 47 "synchronism of rpm sensors" is additionally stored if implausibility with respect to the fuel pump rpm sensor is determined.

Consequences:

• Changeover from start of injection closed-loop control to start of injection open-loop control
  
• Deactivation of boost pressure control
  
• Injection volume limited to 25 mg/stroke
  
• Reduction in driving comfort