Automatic engine off and restart feature is erratic

[Chip]

My 21 Connect has the feature that should shut the engine off when the vehicle stops. It did this regularly for the first year, but now it goes through spells where it works. These spells are getting shorter and mostly it doesn’t shut the engine off. I was never convinced the shut downs saved that much fuel, so I’m not too concerned. Still, I wondered if other members have similar experience, and whether it’s not due to user error of some sort. I know there is a button on the console to disable the feature, and I haven’t touched that.

 

any ideas?

[mrtn]

This is normal for all manufacturers and there is a number of parameters it considers when deciding the S&S. The most likely moment it engages would be driving in nice moderate weather when there's no need for A/C and long enough stretches between stops to have the battery charged. The more load you put on accessories the less likely is the shutoff.

[Don Ridley]

Start-Stop is very dependent on the battery capacity (state of charge). Some vehicles have a separate battery for SS but I don't the the TC is one. The extra battery helps keep the battery SOC high and make the SS more reliable. As mrtn said, there are lot of paramenters that will disable SS like ambient temperature so it's common in hot climates for SS to not run frequently.

Edited March 11, 2023 by Don Ridley
spelling

[Chip]

I’d observed that S&S works differently on 90+ days, suspected cold temps might have an impact, and figured it wouldn’t trigger before the engine was warm. Most of my driving is in Maryland, where temps trend toward moderate, and is the same as when S&S more regularly functioned.
 

I hadn’t considered the battery, which maybe is weakening after two years. Will have to check that out. My use of accessories is mostly limited to radio and cell phone, which I wouldn’t consider a heavy load.

 

I’m not so concerned that I want to take it to the shop, just curious to know what’s going on.

[Phil0110]

It's also worth noting that the engine stop-start feature may not be suitable for all driving situations. For example, if you frequently drive in heavy traffic or make short trips, the feature may not activate as frequently. If you're concerned about the performance of the feature, you may want to check with your dealer or mechanic to ensure that there are no underlying issues with your vehicle.

[TINole]

Anyway to disable this annoyance permanently?

 

 

[mrtn]

There are model specific buttons for sale that replace the oem button and disable the function at startup but retain the possibility to re-engage.