General information on the auxiliary heating system of the E65

This document provides general information as well as the procedure in the case of a locked auxiliary heating system.

Information on locked auxiliary heating unit

Causes of a fault lock-out can be:

• Undervoltage cutout
  
• Overheating protection function triggered
  
• Lack of fuel
  

That is, a fault lock-out occurs when a fault is detected during operation and the auxiliary heating system switches off. Thereafter, the auxiliary heating system only needs to be switched off ones with the telestart transmitter to cancel the fault lock-out.

After three successive faults without successful combustion, the heater lock is activated.

Unlocking the heater lock:

The service function 'Unlock auxiliary heating system' must be run AND then the fuse of the auxiliary heating system (cut off voltage) must be pulled.

General information and notes

Information regarding disruption-free use of the auxiliary heating system.

• Avoid undervoltage; check the battery and alternator; explain the problem of short distance driving to the customer. In the case of undervoltage, it can also occur that the integrated automatic heating / air conditioning system (IHKA) does not send a start telegram to the auxiliary heating system and thus no independent heating is possible. Please always read out the IHKA fault code memory and/or include it in the diagnosis of the independent heating.
  
• When the fuel tank is at reserve, auxiliary heating is not possible in any situation. There does not have to be a fault lock-out.
  
• Smoking: the auxiliary heating system is a vaporizing burner, i.e. during short-distance driving the burner receives a rich mixture a number of times and smoke can develop due to the design principle. The short combustion phases mean there is no burn-off.