Camshaft Hall-Effect Sensor DDE 4.0

The camshaft Hall-effect sensor is mounted at the top front of the cylinder head cover. A rectangular lobe which moves past the Hall-effect sensor is located at the front of the camshaft. The DDE control unit evaluates the resulting voltage signal (one square-wave signal per camshaft revolution). This signal is used for synchronization purposes:

With the aid of the camshaft signal, when the engine is started, the DDE control unit determines whether there is an injection or a gas flow TDC and can thus activate the correct injector for fuel injection.

Engine start is not possible without synchronization!

Troubleshooting

The following faults are monitored:

• Signal frequency too high
  
• Signal failure
  

In both cases, fault code 1E25 "rpm sensor monitoring" is stored each with different types of faults.

Consequences:

• In case of failure during engine operation: No effect, however, the engine will not start during the next start attempt.