Crankshaft Position/RPM Sensor DDE 4.1

The inductive crankshaft position/rpm sensor is screwed in the transmission bell housing. A pule generator wheel with 58 small gaps and one large gap that moves past the crankshaft/rpm sensor is located on the flywheel. The DDE control unit evaluates the resulting voltage signals for the purpose of calculating the engine speed.

Both control units require the engine speed signal. For this reason the slave control unit sends the engine speed signal via the P_INK line to the master control unit.

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
  
• Rail pressure control
  
• Idle speed control
  

Troubleshooting

The following faults are monitored:

Fault codes 0335, 0336 "Crankshaft speed"

• Overspeed recognition (engine overspeed)
  
• Signal dynamically implausible
  

Fault code 1E25 "rpm sensor monitoring"

• Crankshaft signal line from slave to master defective
  
• Failure of rpm sensor signal, crankshaft
  
• Crankshaft position/rpm sensor signal dynamically implausible
  
• Monitoring from slave
  

Fault code 1E26 "rpm sensor monitoring"

• Failure of rpm sensor signal, crankshaft
  
• Signal dynamically implausible
  

Consequence:

• Engine shuts down