Happening in a 2015 85D w/ sw 2020.48.37.1, but just started manifesting itself the past two weeks.
I've started noticing intermittent failure of the interior blower fans to start when the AC is started.
The first two instances were the first ~3 minutes of opening the door and the AC turning on before the blower kicked on; the incident yesterday escalated to a 15 min drive, followed by a soft MCU reboot and another 5 min of driving before finally turning on.
This is a situation where there is zero-flow out of any vent, not just a weak flow. The car thinks AC should be running, because the exterior fans run as appropriate, and when the blower does kick on, the air is immediately cool from the compressor running. The app is showing a believable car interior temp, so I do not believe this to be a temp sensor issue. It is intermittent, so blown fuse would not make sense. Range mode and cabin overheat not active.
Playing with AC settings on this most recent failure mad no difference - switching from auto to manual, cycling AC on/off, changing temps, syncing/unsyncing temps, switching floor/dash/windshield vents, changing blower speed, etc. There was just some point where the car finally decided "Ok!" and the blower came on.
Since the first instance the car has gone on a multi-hour trip with no HVAC issues.
I'll do a hard reset and start logging times for a service ticket if it continues, but in the interim, anyone have experience with similar failures?
I've started noticing intermittent failure of the interior blower fans to start when the AC is started.
The first two instances were the first ~3 minutes of opening the door and the AC turning on before the blower kicked on; the incident yesterday escalated to a 15 min drive, followed by a soft MCU reboot and another 5 min of driving before finally turning on.
This is a situation where there is zero-flow out of any vent, not just a weak flow. The car thinks AC should be running, because the exterior fans run as appropriate, and when the blower does kick on, the air is immediately cool from the compressor running. The app is showing a believable car interior temp, so I do not believe this to be a temp sensor issue. It is intermittent, so blown fuse would not make sense. Range mode and cabin overheat not active.
Playing with AC settings on this most recent failure mad no difference - switching from auto to manual, cycling AC on/off, changing temps, syncing/unsyncing temps, switching floor/dash/windshield vents, changing blower speed, etc. There was just some point where the car finally decided "Ok!" and the blower came on.
Since the first instance the car has gone on a multi-hour trip with no HVAC issues.
I'll do a hard reset and start logging times for a service ticket if it continues, but in the interim, anyone have experience with similar failures?