2012 G37x with 45xxx miles, automatic. No modifications other than LED fog lights.

I typically start the car to warm it up for a few minutes in the AM, key stays in my pocket. Two days ago, I started the car as usual and came back out in 5-10 minutes. It seemed like the idle was a little rough but it didn't really catch my attention. I got in and started to drive and noticed the solid red security light (car profile with key in the middle) on the dash. I stopped the car, turned it off, and started it again. It stalls. Powered off, then started again. It stalls again. Tried a third time. And caught the accelerator with enough to keep the car running, and drove home. Nothing abnormal other than the red security light.

Got home, turned the car off, started, no issue except security light. I let the car cool off for about an hour, armed and disarmed the alarm, tried to start and it almost stalled but didn't.

On the way to the dealer, over the course of about 3-4 minutes, the red security light faded out VERY slowly. (Almost like it was running of a capacitor that was slowly loosing power.)

The dealership found nothing and had no issues this AM.

Does anyone have ANY ideas?

Thanks in advance!

 

Strange...
Let's start with the basics and check the battery voltage:
(1) With the car off, after the car has not been used for a few hours
(2) With the car running

On some other cars, the alarm system can get confused if the battery has low voltage.

 

Very good idea, thank you!

What would be the target voltages for each? Still 13.7 +/-?

 

After sitting for a few hours it should be around 12.6 volts.
With the engine running around 13.8 - 14.4 volts.

 

12.7 cold (about 12 hours)

14.6 running

 

Battery seems good. Was there any corrosion around the battery posts?

Does this happen every time you start the car?
Is the idle steady or does it hunt up and down a little?

I am thinking there are two issues:
(1) Security light
(2) Rough starting / idling

The rough starting / idling may be due to dirty throttle bodies.
Tonight I will read the security alarm section of the FSM and understand the criteria for the red security light to be on.

 

Agreed. Posts look great, barely even grayish and no corrosion. Cables tight

No, it only happened once and I've been warming up the car the same way since I bought it last Spring. Albeit not every day, but certainly when it is below 35 or so.

Cold idle seems a little rough to me, especially compared to idle when warm. It might hunt the width of the tach needle, but visually it is barely noticeable. The sound (to me) seems rough.

I didn't drive it yesterday and I didn't pay attention to the idle when I tested the battery earlier, so I didn't notice the idle at all. The only reason I'd link them together would be due to the stalling a few days ago, which was quite abnormal. It has have had the security light issue or a stalling issue since I've owned it and put about 15K on it.

FWIW, my dad's 2009 G37x stalled when he took a hard turn. Once stopped, it started right back up. That was due to a software upgrade for the ECU, but this one is up to date.

I never thought to look up the FSM for this. Is it available? (I had a digital copy when I had my STi and used it ALL the time.)

As for cleaning the throttle bodies how intensive is that job on this car?

Thanks so much for your help!

 

Here is a link to your FSM: Index of /FSM/G37/Sedan

If your idle is not hunting up and down, I think your throttle bodies are fine. Cleaning them is not hard, but you do need to do these procedures after cleaning them:
(1) Accelerator Pedal Released Position Learning
(2) Throttle Valve Closed Position Learning
(3) Idle Air Volume Learning * most important, or your idle will be high. *
Details of the procedures is in the FSM in the EC section.

See: https://www.myg37.com/forums/d-i-y-i...le-bodies.html