Engine Coolant Temperature Sensor DDE 3.0

The temperature sensor is screwed into the cylinder head and registers the coolant temperature by means of its variable resistor (NTC= Negative Temperature Coefficient).

The coolant temperature serves as a measurement variable for following functions:

• Exhaust gas recirculation
  
• Injection volume calculation
  
• Limit volume calculation
  
• Start volume calculation
  
• Start of injection control
  
• Control condition for air conditioning system
  
• Deactivation of boost pressure control due to cold start
  
• Preheater time control
  
• Electric fan activation
  

Troubleshooting

Fault code 35 "engine coolant temperature sensor" is stored if the temperature sensor is defective.

Test note

The temperature sensor is destroyed by a short to B+.

Setpoints for resistance check

• Resistance at 20 °C: 2.5 ... 3.0 kOhm
  
• Resistance at 50 °C: 0.7 ... 0.9 kOhm
  
• Resistance at 100 °C: 0.12 ... 0.17 kOhm