Auto Stop on 2015 Impala

My 2015 Impala has Auto Stop. Sometimes it works, sometimes it does not.
I know about the general operating parameters. But this is more like: It works fine today. The next day not at all. Is there a switch or sensor somewhere that might malfunction? The Auto Stop battery seems to be OK, and the instrument panel say that the charging voltage is good. Any ideas?

Doesn’t your manual mention a way to disable that feature, at least temporarily?
My friend’s new Forester has Auto Stop/Start and after doing a comparison over several tanks of gas he found that the “saving” amounted to something like .3 mpg.

The annoyance of that feature, coupled with a lack of substantial savings, causes him to disable it each time that he starts the engine. Unfortunately, this can’t be done permanently on his car, but maybe it can be done on your car.

If the car’s compiter determines all the conditions are not favorable to start stop, it is disabled. Much more than just the battery.

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How long have you had this vehicle and is this a new problem ? Battery seems OK ? If it is the original battery it may not be strong enough for the stop/start function .

If the engine does not restart when you move your foot from the brake pedal to the accelerator, that is a problem.

If the engine continues to run while at a traffic light, the heater and air conditioning will continue to operate, is that a problem?

This is correct. My 2019 F-150 has auto stop/start. But there are conditions that need to be met in order for it to happen;

If it’s hot out and the A/C is running on max cooling, it’s disabled
If it’s cold out and heat is running on full, it’s usually disabled
If the truck hasn’t been driven for a while and the battery is even slightly discharged, it’s disabled
If you’re towing anything, it’s disabled
If you’re in 4WD, it’s disabled
If you’re in manual shift mode, it’s disabled
If you’re in any gear but “Drive” it’s disabled.
Sometimes it’s just randomly disabled, and the info screen in the gauge cluster, will let you know that the next time you come to a complete stop, the engine will cut off.


The problem with this gizmos is that you will be replacing your starter more often since the engine shuts down and restarts every time you come to a complete stop. There is no saving to be done.

Had it since new. 31k miles now.
The puzzler is that the feature stopped working for months. Then on Tuesday, started working normally. Next day, Wednesday, not working again. Still not working. It appears to be something other than the battery. I don’t care if it works or not. I’d disable if there’s a way.
Guess I’ll have to see the dealer.

The Owner’s Manual doesn’t provide any information regarding how to disable it, even on a temporary basis?


There are devices for sale on the internet that are installed on the hood connector that disable auto stop . They are said to work well, but they somewhat interfere with normal remote start operation. Not an issue if you don’t have remote start. These devices work on the premise that auto stop is disabled if the car is started with the hood open.

It’s intermittent. Some days it works other days not.
I’m thinking there is a stuck switch somewhere related to the brake pedal.
Both batteries seem to be OK.
I’d like to know more before seeing the dealer for my own information.
Not that I don’t trust dealerships. But sadly, I don’t trust dealerships.

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This is off a chevy site .
All Stop/Start systems operate fundamentally in the same way. It is not a simple system .
The following vehicle conditions must be met for an Auto Stop event to take place.

Initial minimum vehicle speed during the drive cycle must reach 12 MPH (19 km/h). Subsequent minimum speed may vary from 1-6 MPH (2-10 km/h), depending on the vehicle.
In a vehicle with a manual transmission, the transmission must be in Neutral and the clutch pedal fully released.
Ambient and engine coolant temperature correlation must meet specified values.
Ambient and transmission fluid temperature correlation must meet specified values.
Hood switch status is closed.
Brake pedal is depressed beyond a specific value (approximately 27%).
Accelerator pedal is in the learned home position.
Brake booster vacuum is greater than 45 kPa (7 PSI).
Transmission gear selector is in the Drive position.
Vehicle speed is less than 3 MPH (5 km/h).
Engine speed is below 1500 RPM.
Engine coolant temperature is less than 248°F (120°C).
No A/C compressor request from the HVAC system (A/C or Defrost modes).
Battery voltage greater than 12 V.
Battery state of charge in the ECM is greater than 75% (changes with state of health).

Get a flashlight & take a look in that area. See anything unusual like debris against the switch, springs or fasteners missing, bushing worn out, etc?

Dealer says there are no switches. I didn’t see one either.