John,
What makes you sure that a low battery warning is the HVAC ECU..?? It could be that the battery is starting to go, or the alternator is not giving sufficient charge. If the battery has a duff cell and is not putting out full volts, or is low on current, then some of the systems may shut down due to insufficient power. I would check these before going any further.
Cheers
R
Hi again! When I mentioned this to my tech he informed me that the "low batt" message in the infotainment section is indicative of the HVAC.
(the "low batt" message shows beneath the fan speed indicator)
As they checked the alternator, and replaced the battery, there's no reason to suspect the issue is in the charging. The whole charging system checked out A-okay.
The other side of this is that the "E" shows for a few seconds when I start her up in the mornings, and even comes on sporadically when she's warmed up.
It can mean the ambient temp sensor is failing (the one on the side mirror) but they said this is a also a possible sign that the HVAC unit is on the way out apparently.
I'm not rushing into this at any rate. I can live with it for now, but eventually, I'll unplug the old and plug in the new!
Cheers!!