Road speed signal DDE6.0/6.2/6.3

The vehicle's current road speed is signalled to the DDE control unit by the DSC control unit via the CAN bus.

The road speed serves as a measurement variable for the following functions:

• Control condition for air conditioning system
  
• Oil pressure warning lamp activation condition
  
• Limit volume calculation
  
• Injection volume calculation
  
• vehicle speed control
  
• Gear recognition
  
• Idle speed control
  
• Electric fan control
  

Troubleshooting

The signal is checked for plausibility and monitored for the following faults:

• 3F50, Road speed too high
  
• 3F52, Invalid signal
  
• 3F53, Plausibility in conjunction with injection volume and engine speed