I would be grateful for any insight anyone has to offer, a ground problem seems most likely but I am open to ideas. I drove from Wi. to Bowling Green Ky. last Thursday for LS fest, About 2 hours to go with the outside temp reading 97 degrees the ac blower just quit. I checked the fuses, they were good and I could hear the compressor clutch engage when I turned the system on so I thought the fan must have failed and I would replace it when I got home. Then on Fri. I was in the auto cross grid waiting for a run when the car would not start. The head lights stayed bright but the dash went blank when the start button was pushed. I tried moving the shifter from neutral to park and back with no difference . A few minutes later the car started like normal . The rest of the week end everyhing seemed normal except the ac fan not working . On Sunday I filled up with gas to start for home and saw that the compas in the mirror was blank and the information center below the gages was also blank. About 2 mile down the road they both came back on and the ac blower started blowing again.The rest of the way home all was normal. Then today when I shut it off it beep and the message "NO FOB RESTART?" was displayed. I tried restarting and it started normally.This is on a 2013 GS.

 

The car might need a new battery.

 

Since the Blower motor quit after 7 hours of driving with the voltage at near 14 volts the battery causing that seems unlikely. I am going to focus on the grounds ,in particular G202 in the pass foot well. It provides ground for the blower motor processor, inside mirror relay, HVAC control module and body control module among others.

 

Maybe a short somewhere in the hvac circuit. Time to get the meter out! good luck
edit: Did you have a passenger? sometimes the plugs get kicked and cause weird issues.

 

Sometimes, even with a bad battery, our cars will start and run (mostly) fine.
I would get yours load tested.
Or, try a extended, no start, engine turn over.
Weird problems are often a sign of a bad/weak/bad cell battery.

 

Cleaned the G202 ground, it looked Ok. Everything is working as of now . If the problems reoccur, I will be back to let everyone know.

 

Well I have new gremlins . No fob detected ,Fob does open door and trunk and sound horn. Car starts with fob in the slot. BCM shows codes U1096, U1153,U1193,U2108 and U1305. I also went into low power mode and had a throttle pedal code set, the car went back to normal after restart.. C5 Diag any help for were to start would be appreciated .

 

Just went out two hours later and everything is back to normal. Hard to trouble shoot.

 

🤔 Check the shifter linkage under the boot. If it's a little loose it might prevent it from starting. The cable and shifter are connected with circular, brittle-prone-plastic piece; and had completely broken apart. Easy enough fix, but will require some digging 😉

 

If it was only a no start this would have merit, combined with the other symptoms it does not seem to fit.

 

Maybe, but it's simple enough to check under the boot, might be worth your while as you narrow down the list. Your description of the car's symptoms reminded me of the same, it took me about a few months before the car became a paper weight in my garage. When the linkage is loose, it will cause all kinds of chaos.

 

I pulled and inspected the BCM connectors. I did not see any obvious problems, so I sprayed them down with electrical contact cleaner and reassembled. As of now everything is working. If the Gremlin reoccur, I will update.

 

I have been trying to put some miles on before it is time for storage, so far every thing is working perfectly . Fingers crossed.