Help relating to troubleshooting in independent heating system

This help program gives detailed advice on fault finding in the event of problems with the independent heating system.

List of known symptoms:

• No possibility of switching the independent heater on at the MID or on-board monitor.
  
  If no display appears after the ignition key has been turned to position 1 and the selection made to activate the independent heater, the fault could be an IKE not coded for an independent heating system.
  
• After switching on the independent heater and changing the display in the MID or on-board monitor to switch-off mode, the latter will immediately switch back to switch-on mode.
  
  If the display switches back immediately, it may be due to an open circuit in the "wake-up" or status leads, or possibly a defective independent heating system control unit.
  
  The heater control unit emits a voltage of 12 volts on the "wake-up" wire when the system is switched on. The telestart receiver limits this voltage to a value between 6 and 9 volts so long as the wiring is OK. The receiver forwards a voltage of about 6 volts to the independent heater unit. The heater control unit is informed via the status wire whether the independent heater has started. If no signal is received, the starting procedure is abandoned.
  
• After switching on, the independent heater starts up (combustion air blower can be heard), but switches off after about 5 minutes (2 starting attempts and malfunction after-running).
  
  The independent heater was able to be activated via the "wake-up" wire and emits the feedback to the heater control unit through the status wire that it is in the start phase.
  The MID or on-board monitor display remains in the switch-off mode. That means that the "wake-up" and status wires must be OK.
  If the overheating fuse is activated or a component of the independent heating system is defective, preventing the system from starting, a second start attempt is made. There is then a phase of malfunction after-running and the independent heating system switches off. The MID or on-board monitor changes back to switch-on mode.
  
  In this case, the independent heater unit should be checked for defective components or activated overheating fuses using diagnosis. This can also be done by calling up the flash code output at the glow plug voltage supply when the malfunction after-running phase is completed.