Delete Auto Stop/Start on 2025 (Not the temporary button)

[penright]

This has been mentioned in a few threads. Not wanting to hijack any of them, I thought I would just start one. Someone asked if the "hood wire" was the same as 2024. Again, the subject of the thread was something else and I did not want to hijack it. Also in another thread different subject, I noticed @CocoaJeff signature auto stop/start had a line through it, thinking it was deleted. Didn't think it was appropriate to ask him in that thread.

So, I started this one. I found this article https://gmauthority.com/blog/2019/0...l-disable-your-engine-auto-stop-start-system/ and there are items for sale on Amazon from $15 to $100. I am guessing that is why the one thread was asking if the plugs on the 2025 were the same asthe older Equinox. Thoughts?

 

[davem]

I installed the Amazon $15.99 cable on my 2022 Equinox Premier. I did contact the seller and received an immediate response to my question. I'm sure you could easily verify that they support the 2025 Equinox. A chart in their description does state that the small plug version supports vehicles produced after and including 2019.

Here is the link to what I purchased: https://www.amazon.com/dp/B0952X1JWH

It works great and does not interfere with the keyfob's remote start.

 

[PoManNox]

Is there easy access to the hood switch harness on the 2025? I doubt GM changed the configuration of the small two-pin connectors, but you never know.

 

[penright]

I'm sure you could easily verify that they support the 2025 Equinox.

I just ask them, after some more research I now understand the big vs small connector that @PoManNox was saying. I think that was the question someone else as asking. The article to the link I posted talk about a relay so after the open hood is faked out, the relay kicks in so the computer thinks the hood is closed to keep the open hood light out. Does the one you have for your 22 keep the hood open light out? From the picture does not look like there is much room for a relay.

 

[CocoaJeff]

Hi, Penright;

This is the one that I bought:

https://www.amazon.com/dp/B0D7CHCVK2?ref=ppx_yo2ov_dt_b_fed_asin_title&tag=chevyequinoxforum-20

I cannot say whether or not it works on the 2025. But as others have mentioned, just try contacting the seller of one of those devices and see if they have further details.

As for my signature, when I created it I listed the auto-start / stop feature. After I installed the pigtail, I just put a line through it instead of deleting it... basically showing that my car had the feature, but that it was disabled.

 

[penright]

but that it was disabled.

That is what I assumed, that is why I was asking about your experience. Does your model turn off the open hood light?

just try contacting the seller

I am asking about the one you posted also. My guess is I need to look when I can and if it is the same connector as 2024 it should work.

 

[CocoaJeff]

I can confirm no problems at all. As others have mentioned in other threads, the light on the button on the dash stays on, but it does not auto start stop. Acts like the button was pushed. No check engine light or open hood light, and remote start still functions. I was able to start the car (via the start button inside) with the hood open. If I didn't know the pigtail was installed, I would never know it was there. Best $12 bucks I've spent on the car.

 

[davem]

I just ask them, after some more research I now understand the big vs small connector that @PoManNox was saying. I think that was the question someone else as asking. The article to the link I posted talk about a relay so after the open hood is faked out, the relay kicks in so the computer thinks the hood is closed to keep the open hood light out. Does the one you have for your 22 keep the hood open light out? From the picture does not look like there is much room for a relay.

I have never seen a hood light come, no check engine light either. The only time I remove this cable is when I have to take it to the dealership for warranty repair.

 

[CocoaJeff]

I have never seen a hood light come, no check engine light either. The only time I remove this cable is when I have to take it to the dealership for warranty repair.

Hmmmm.... good point to remember...

 

[penright]

Got some pictures. @CocoaJeff do you have the hood latch and what looks like a hood sensor?
This is from the driver toward the passenger side. For $12 I think I can just take a chance.




Here is the shot of the actual latch connector ...

 

[PoManNox]

Looks identical to my 2021.

Your lower red arrow is pointing to an impact sensor for the airbag system. Same location and core support design from 2018+

I'm not smart enough on this topic to understand exactly how these work, but I believe if you open up the loom/tape on the bypass harness, you'll find a resister in there on one of the legs. They allow the hood open / hood closed functionality to work perfectly with no codes and no remote start issues, but somehow they prevent A/S/S from working.

 

[CocoaJeff]

I agree with PoManNox, that sensor that you're pointing to with the second arrow is an impact sensor. Here is how my setup looks:





I just unplugged the current connector (a task in itself), plugged in the device, and then zip tied it to the current cable.

 

[penright]

but I believe if you open up the loom/tape on the bypass harness, you'll find a resister in there on one of the legs. They allow the hood open / hood closed functionality to work perfectly with no codes and no remote start issues, but somehow they prevent A/S/S from working.

The article that I linked to above talks about a relay. When nothing is running, the relay is closed, so the system knows the hood is closed. All works as expected. When the engine starts, it opens the relay, so now the computer thinks the hood is open. Looking at the picture, the wire loom did not seem big enough to hide the relay. I may have to open the loom and see what is inside. That is why I was asking what I was asking. I don't know how they can make it as cheap as they do with just the parts cost.

Thanks, @PoManNox and @CocoaJeff for your time. The response from posting the question on Amazon, customers were saying something we were. Looking at the picture last night I thought it was close and cheap enough that I pulled the trigger and bought one. This morning the vendor responded that it would not work. So if it does not work, I guess there is more to the circuits than just an open/close switch or relay.

 

[CocoaJeff]

Well, hopefully it will work for you. If not, just return it and watch for one that says it can work on a '25. As much as people hate this "feature", I'm sure there will be one available for your model, soon.

 

[penright]

It should get here today, but curiosity got to me. I have been thinking about what @PoManNox said about resisters. BTW, thanks for sending me down a deep rabbit hole.
When you need to know if a switch is open and if a wire is broken, you use a resistor. Depending on how the switch pulls the line, the only way it would max out (high/low) is open wire otherwise the voltage swing will be somewhere in between.

Using the information provided, which is for 2024, looks like there are two signals one for theft/remote start safety (BN/GN). The other is to disable auto stop/start (YE). So pin 1 gets switched from 732-ohnms to around 2.3k-ohms when the hood is open and the switch is toggled. So the only one it needs to interrupt is the wire on pin 1. Just need a diode for protection and a 2.3K-ohm (732+1580) resistor to ground. Now the question is, does 2025 operate the same way?

Hood Ajar Operation – Body Control Module​

The BCM applies B+ to the hood ajar signal circuit and monitors the voltage to determine the position of the hood. The hood ajar switch contains a multiplexed resistor. This resistor will vary the voltage seen by the BCM by pulling down the applied voltage based on the position of the switch. The body control module uses to hood ajar input as a means to determine if unauthorized access has been gained to the underhood area during a theft attempt. The body control module will also disable remote vehicle starting (if equipped) when the hood is ajar.

Hood Ajar Operation – Engine Control Module (with KL9)​

The engine control module applies B+ to the hood ajar signal circuit and monitors the voltage to determine the position of the hood. The hood ajar switch contains a multiplexed resistor. This resistor will vary the voltage seen by the engine control module by pulling down the applied voltage based on the position of the switch. The engine control module monitors the hood ajar input as a disabling condition for a 12 V stop/start event.


I saw it talking about KL9, I thought it had something to do with Auto Stop/Start. In searching I found a description of the sequence. It can restart a stopped engine in .3 seconds. It engages the starter gear into the flywheel as the engine is spinning down. The article describing it is for a 2028, but I bet it is the same on newer cars. https://gm-techlink.com/wp-content/uploads/2017/12/GM_TechLink_22_Mid-November_2017.pdf

Here is a screen capture of the relevant information.

 

[CocoaJeff]

Boy you did go down a deep rabbit hole!!! I'm curious to hear if it works for you.

 

[penright]

Boy you did go down a deep rabbit hole!!!

I'm going to blame it all on PoManNox That is what he gets for being right

 

[penright]

Did not work. Plug seems correct. It set a BCM code. Circuit High means there is no resistance pulling it down to ground.


I pulled up the ECM and was looking at the hood switch under the Autostart Inhibit Reason - Ajar and it was set to No if I opened the hood it would switch to Yes.



The cable looked as I would expect, I will include some pictures, so I am starting to think they switched wires and/or changed the resistor values.

I don't suppose anyone has access to GM that can check the schematics and/or theory of operations. Everything I see does not have 2025 in it.

Factory black to black, brown to red, and yellow to green. The black ground is pin 3.

If you hold the lock to the top Factory (Red) Pin 3 is on the right, if you turn the above picture around. That means yellow is 1 and the brown/green strip is number 2. So if you translate that to the just bought one, then black is ground, yellow (#2) is now BCM and the ECU (#3) is not connected. Which is what I would expect.





So brown (#1) would be the ECU and I assume under the heat shrink is the diode and resisters. Which is what I would expect.

 

[PoManNox]

Does it light the check engine light? I wonder if GM changed the resistance value for 2025.

I have heard of some of these cheap amazon harnesses not working, where one from another seller worked.

 

[penright]

Does it light the check engine light?

No light, i just saw the code when I connect the scan tool.

I wanted to see if I could see the switch. I may do some looking under the shrink tube when I get to work. I may try to back prob the voltage to see what kind of resistance. Because of the diodes you just can't just read ohms.