This is a curiosity thing mostly, and frankly not something I am going to look into as I hate auto start / stop. But my newly aquired used truck, does not auto stop when coming to a red light (like all the trucks next to me). When I bought it, the starter was replaced 300 miles prior with a new ford unit. In the PCM there was a trouble code for "Starter Performance" , and RR tail lamp short or open circuit. I fixed the bad bulb and cleared the codes. After all emmissions monitors completed there are no hidden codes yet it does not auto stop. Any ideas?
2018 F-150 not auto stopping thankfully.
- Thread starter Fordiesel69
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Funny you mention this. I bought a slightly used 2020 Explorer in 2022. Start/stop never worked and I did not mind that one bit. I assumed the previous owner figured out a bypass for it. Then one day about a year or so later, the start/stop just started working again. I have no idea what caused it to start working. There is a button to turn off the start/stop, but it's reset every time the car is turned back on.
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Typically they monitor battery voltage to make sure it's healthy enough to shut off while still running electrical loads (like blower motor, stereo etc) and start again. And of course you don't want to be doing repeated starts with a battery that isn't near full charge as it could affect long term battery life.
Thus I get nervous when they don't work.
There are also other things that disable it like Max A/C and other stuff I'm forgetting
Thus I get nervous when they don't work.
There are also other things that disable it like Max A/C and other stuff I'm forgetting
There are several reasons the start/stop doesn't activate. Those include, a weak battery, or climate control, and other things. However-it could be possible the BMS near the battery has been unplugged, or a defeat system was installed behind the switch.
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^^ These two posts right here. The first thing that happens on my car when the battery gets low, is the start stop function quits working.
A quick charge with my NOCO 5 and it's back in business.
A quick charge with my NOCO 5 and it's back in business.
Is the battery under the hood a regular lead acid or an AGM?
You should be able to flip through your screens on the dashboard and it will give you a relatively generic reason. Common reasons my start stop is not engaging include: vehicle is charging (BCM believes the battery state of charge is below the desired level - normally 70% on my F150), temperature is too low (which can be the ambient air temp - well below zero and the system shuts off, or it can be the inferred battery temp - when below roughly 32, my start stop won't engage, or the engine coolant temp is still below roughly 130F), accessory usage (normally the inverter is the one the makes this happen), or it also won't shut off if the front windshield defroster is on or on in any combo with the vents or floor.
There are a large variety of combos that may make it not use start stop. If you want specific reasons, you can use a tool like forscan to see the exact reason it is not engaging that is more specific than the generic menu items.
Both my 16 F150 (with the 2.7) and the 21 Explorer work similarly.
There are a large variety of combos that may make it not use start stop. If you want specific reasons, you can use a tool like forscan to see the exact reason it is not engaging that is more specific than the generic menu items.
Both my 16 F150 (with the 2.7) and the 21 Explorer work similarly.
Like it myself. Come to a red light and you get silence and smoothness.
My 2020 F150 calls for an AGM.
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In my F150, it's "not working" because I installed Autostop Eliminator. Lowered my blood pressure 10 points. Perhaps the previous owner of your truck did the same?
If 12V battery health is questionable, the ESS will often not work. This isn't just a Ford thing, but across the industry. The parameters used by the onboard system are often tighter than what battery testers deem to be acceptable, so beware.
Some do install non-AGM batteries because they are cheaper. It's my understanding BMS is setup up for an AGM. But if you unplugged it-it doesn't matter I guess.
You know-I get in my truck, put my seatbelt on so I don't get the chime, push the start button and immediately the start/stop button. It's automatic to me-and doesn't raise my blood pressure. It's not even worth the $100.00 bucks to me for the work around you have.
I can get an off brand AGM (sold by one of those independent battery places) for $100.00 to $125.00. I think the later has like a three year guarantee. I have no idea where they are made.
Yes
I'm not jumping through hoops to prove what a battery costs. I just check the costs as little as a month ago. They specialize in commercial diesel batteries. A very small operation.
They don't ship-they don't have a website.
