Removing ECM safely

[Caligirl]

So I gave my husband the link for LT1swap.com (for deleting AFM on my 07 Tahoe) and although he hasn't read it all through yet, he was concerned about frying the computer if the ECM is not removed/put back correctly.

Can anyone attest to the ease/difficulty of this project? The LT1swap.com site includes a video for removing it that looks pretty straightforward, but the instructions for prepping and cleaning the connectors looks to be pretty detailed and a little intimidating with all the warnings. Any problems with any of the steps? And if you don't have an air hose, other options?

Thanks

 

[OR VietVet]

Use of a "ground strap" is critical IMO. To easy to mess up without it and all the info for cleaning the connectors is also important. Make sure pin alignment is correct as well. Check all female connectors to be sure they stay in the connector holder if pushed from the pin side. There have been times where when plugging everything together causes a female connector to push out of the holder. That causes either no connection or intermittent connection issues. If you have watched just one you tube about all this, do yourself a favor and watch a few and compare them.

 

[swathdiver]

Why are you removing the ECM to delete AFM? Are you sending it out to someone?

 

[Caligirl]

Why are you removing the ECM to delete AFM? Are you sending it out to someone?

Yes, we had planned on sending it to the aforementioned service above.

 

[Caligirl]

Gahhhh, so this is such a steep learning curve! Husband looked at the connectors and (outwardly, at least) look very tidy, so probably not a big project to disconnect. BUT while reading the additional info on the site about modifying ECMs with GM updates (if not previously done), there was this info and warning:

"To see what updates maybe available for your vehicle, click here, enter your VIN, click 'Get CAL ID', Select 'ECM Engine Control Module', click 'Next', and click 'Complete History' This will show all software for your ECM specific to your VIN#. There are 8 modules in your ECM. Some scan tools will display what your current vehicle software is, and you can use this tool to see if updates are available, and what that update is for....

....Please note, an ecm which is programmed with NEW GM software, may require a relearn procedure once you get it back in and running. If you get P0315 code, this will mean you need to have a "crankshaft position sensor variation lean" procedure done with a scan tool. This code will not cause any poor running or issue, but will prevent ECM from detecting misfires until the relearn is completed."

What in the world is this scan tool and who/where/how much will this cost so we can know which of those updates have been done or if we even want/need them done, as well as fix the possible P0315 code? I was able to bring up the chart of said updates, but yet again, over my head.

 

[Jason in DLH]

Gahhhh, so this is such a steep learning curve! Husband looked at the connectors and (outwardly, at least) look very tidy, so probably not a big project to disconnect. BUT while reading the additional info on the site about modifying ECMs with GM updates (if not previously done), there was this info and warning:

"To see what updates maybe available for your vehicle, click here, enter your VIN, click 'Get CAL ID', Select 'ECM Engine Control Module', click 'Next', and click 'Complete History' This will show all software for your ECM specific to your VIN#. There are 8 modules in your ECM. Some scan tools will display what your current vehicle software is, and you can use this tool to see if updates are available, and what that update is for....

....Please note, an ecm which is programmed with NEW GM software, may require a relearn procedure once you get it back in and running. If you get P0315 code, this will mean you need to have a "crankshaft position sensor variation lean" procedure done with a scan tool. This code will not cause any poor running or issue, but will prevent ECM from detecting misfires until the relearn is completed."

What in the world is this scan tool and who/where/how much will this cost so we can know which of those updates have been done or if we even want/need them done, as well as fix the possible P0315 code? I was able to bring up the chart of said updates, but yet again, over my head.

A “Tech 2” might provide this information. Others will chime in to where you can get one for the least amount of money and whether or not it can actually perform this.

 

[exp500]

Try something like this with an old laptop/tablet-Vxdiag VCX Nano for GM/Opel Diagnostic/ECU Programming Tool
Or this stand alone-Vetronix GM Tech2 with Case for GM/SAAB/OPEL/SUZUKI/ISUZU with Candi Module Tech2
Pros and cons to each, I like the Nano.

 

[TJ Baker]

Some scan tools will display what your current vehicle software is

With regards to getting this information you don't necessarily need to spend more than about $20. A Bluetooth OBD2 adapter and an android app can read this. It is a standard service $09 request to the ECM. (This device will NOT do the Crank angle sensor error relearn)

I use a VeePeak Mini Bluetooth adapter and the OBD Fusion app for this.

 

[swathdiver]

....Please note, an ecm which is programmed with NEW GM software, may require a relearn procedure once you get it back in and running. If you get P0315 code, this will mean you need to have a "crankshaft position sensor variation lean" procedure done with a scan tool. This code will not cause any poor running or issue, but will prevent ECM from detecting misfires until the relearn is completed."

What in the world is this scan tool and who/where/how much will this cost so we can know which of those updates have been done or if we even want/need them done, as well as fix the possible P0315 code? I was able to bring up the chart of said updates, but yet again, over my head.

Our vehicles were designed to be worked on by the Tech-2, which was the dealer level scan tool from the 1990s until about 2013. GM switched off to something else but the Chicoms kept making them at their factories and sell them for 1/10th the price. Look for my article, The Case for the Tech-2.

 

[Caligirl]

Our vehicles were designed to be worked on by the Tech-2, which was the dealer level scan tool from the 1990s until about 2013. GM switched off to something else but the Chicoms kept making them at their factories and sell them for 1/10th the price. Look for my article, The Case for the Tech-2.

Ahh, ok I was wondering what Tech 2 was in reference to....this is going way over my head. Husband said he prefers working on older vehicles with not so much tech. I concur lol. But I read him the list of available calibrations for our vehicle and he didn't seem to think any on those were make or break. I'm wondering if when the 90k service was done if the service techs generally include or offer to update. We may give them a call to see if they do (extra services, more money, think if they could, they would push that added service...)

 

[Caligirl]

With regards to getting this information you don't necessarily need to spend more than about $20. A Bluetooth OBD2 adapter and an android app can read this. It is a standard service $09 request to the ECM. (This device will NOT do the Crank angle sensor error relearn)

I use a VeePeak Mini Bluetooth adapter and the OBD Fusion app for this.

View attachment 273348 View attachment 273349 View attachment 273350

Thanks. May be a little more than we are willing to try to learn. But IF we do, appreciate the info.

Husband thought the crank angle sensor error relearn happens as you drive the vehicle for a bit after you plug back in the newly modified ECM...or is that something you have to have done by a service?

 

[swathdiver]

Ahh, ok I was wondering what Tech 2 was in reference to....this is going way over my head. Husband said he prefers working on older vehicles with not so much tech. I concur lol. But I read him the list of available calibrations for our vehicle and he didn't seem to think any on those were make or break. I'm wondering if when the 90k service was done if the service techs generally include or offer to update. We may give them a call to see if they do (extra services, more money, think if they could, they would push that added service...)

The only way to know if you have the updated calibrations is to have the scan tool pull them up and then compare that list to what ACDelco has listed for your VIN. GM doesn't recommend updating just for the sake of updating, if your car runs fine without the update, don't bother.

The nice thing about the Tech-2 is that it is the most important tool in the toolbox, it tells you (along with shop manual) what needs doing without any guess work for the most part. I too like the simplicity of yesteryear's cars but which would be more comfortable to drive in everyday or across country, your Tahoe or an old 1980s Suburban? I'm too old and rickety for the former anymore!

 

[swathdiver]

Husband thought the crank error sensor error relearn happens as you drive the vehicle for a bit after you plug back in the newly modified ECM...or is that something you have to have done by a service?

Nope, need the Tech-2 or other bi-directional scan tool. See, the Tech-2 is already paying for itself in your case! LOL

 

[Caligirl]

The only way to know if you have the updated calibrations is to have the scan tool pull them up and then compare that list to what ACDelco has listed for your VIN. GM doesn't recommend updating just for the sake of updating, if your car runs fine without the update, don't bother.

The nice thing about the Tech-2 is that it is the most important tool in the toolbox, it tells you (along with shop manual) what needs doing without any guess work for the most part. I too like the simplicity of yesteryear's cars but which would be more comfortable to drive in everyday or across country, your Tahoe or an old 1980s Suburban? I'm too old and rickety for the former anymore!

Agree!!! We won't tent camp anymore for the same reason haha. Yes, our first used bare bones sub we bought 20+ years had no headliner, just bare metal, so when it rained, or goodness hailed, you couldn't hear the person next to you.

Glad to hear about updates not necessarily being needed. Honestly feel like I keep unearthing more info than I need with each "little" fix.

 

[Caligirl]

Use of a "ground strap" is critical IMO. To easy to mess up without it and all the info for cleaning the connectors is also important. Make sure pin alignment is correct as well. Check all female connectors to be sure they stay in the connector holder if pushed from the pin side. There have been times where when plugging everything together causes a female connector to push out of the holder. That causes either no connection or intermittent connection issues. If you have watched just one you tube about all this, do yourself a favor and watch a few and compare them.

Where would the ground strap be placed?

Tried to find more videos and didn't see many for 3rd gen Tahoes. Are all ECM configurations similar enough to view videos for other makes/models?

 

[OR VietVet]

A ground strap is typically attached as a wrap around the arm of the tech and then clips to the metal under the dash or wherever the tech is. It grounds the tech to the vehicle. There are you tube videos about this. Static electricity can damage an ECM.