Quote:
Originally Posted by gbalthrop
If you had either a short or open circuit in the LIN BUS (Yellow/whatever) wire at the Rear Stratification Flap Motor Connector, then that WOULD prevent activation of any of the Flap Motors "Downstream" or to the RIGHT of the Rear Strat Motor (M4723), which include the Right & Left Mixed Air (Blend) Flaps. So if the default position is Full Heat (100%), then that WOULD result in heat from all front air vents, as the IHKA module could NOT close off air delivery through the heater core. Here is the TIS circuit for your 2009 E90 335xi:
https://www.newtis.info/tisv2/a/en/e...bution/uZS1ONq
It would be interesting to know WHAT the algorith for setting "9C69" is. I was thinking of it in terms of feedback to the IHKA Module NOT reflecting change of position due to faulty motor, BUT I have seen reports of similar flap codes resulting from open circuit in the LIN BUS wire/connectors.
So I SHOULD have qualified my statement: Rear Stratification Flap Motor failure does NOT affect front air vent temp UNLESS the LIN BUS Series Connections are disrupted. AFAIK, a fault in the power supply, ground, or motor itself, which does NOT affect the LIN BUS Yellow/whatever wires, would NOT affect operation of flap motors "Downstream." Anyone with a different concept? 
Thanks,
George |
LIN bus fault makes sense to me. It's just that you'd think the system would be smarter about reporting the nature of the fault.