Symptoms:
No heat through vents, this was a Hybrid Evoque and I found that there was hot air when the engine was running and there was a fault stored with PTC heater 1 No operation.
Fault code: B1DC5-93
Possible cause:
HV coolant heater is locked due to a previous overheating even.
Possible solution:
Unlocking the HV coolant heater via diagnostic procedure.
DDTSB had a document explaining that these heaters can be turned back on or “Unlocked” using diagnostic tool. After following this recommendation the result was that there was a fault with the heater and could not be turned on and also it needs replaced.
Unlock coolant heater procedure:
Attach a battery charger to the 12V battery
Connect a diagnostic tool (i.e Autel MaxiSys Ultra)
Select HAVC control module
Select the function HV coolant heater unlock
Then follow the instructions in the diagnostic procedure.