Intake Air Temperature Sensors DDE 4.1

The intake air temperature sensors are integrated in the air mass meters and measure the temperature of the fresh air drawn in by the engine.

The intake air temperature serves as a measurement variable for the following functions:

• Injection rate control
  
• Rail pressure control
  
• EGR control
  
• Charge-air-pressure control
  
• Preheater time control
  

Function

The DDE control unit supplies the intake air temperature sensors with voltage and ground as follows:

• U_HR, battery voltage
  
• U_HFM1, U_HFM2, supply voltage 5 V
  
• M_HFM1, M_HFM2, ground
  

Depending on the intake air temperature, the intake air temperature sensors return measurement voltages via the A_TANS1, A_TANS2 signals to the DDE control units.

Troubleshooting

If one of the intake air temperature sensors is defective, fault code 0110 ”intake air temperature sensor 2” or 0111 ”intake air temperature sensor 1” is stored and a substitute value is used.