Halp! I bricked my Tahoe (ECU problems)

[Pilot]

First off, I want to mention that I'm a total rookie and have no idea what I'm doing.

I recently had my Tahoe regeared from 3.73 to 4.56. Since then the speedo has been off. I finally decided to take the time today to flash the ECU with my Superchips Dashpaq+ to fix it. I haven't used the Dashpaq in a few years so I guess I forgot the process. I was surprised when well over an hour had gone by and the flash still had not completed. Then, suddenly, the screen on the Dashpaq goes black. I waited another 10 minutes or so and then concluded that it must be done. So I turned the ignition off (it was in the "on" position with engine not running) and then tried to start the truck. It did not start. Instead, crazy lights flashing on the dash and a disturbing buzzing/crackling sound coming from the steering column area.

Now the Dashpaq no longer recognizes the Tahoe. It just restarts over and over again when I plug it in and turn the ignition on. Tahoe will not turn over and all electronics are acting really funky (windows won't move, security warning tone sounds randomly, interior dome lights do light up but really dim....)

Since the Dashpaq had been sitting on the shelf for a few years, I brought it inside and attempted to update the software on the Dashpaq itself. It failed several times and gave crazy error messages instructing me to call Superchips tech support, but it's Saturday and they only operate on weekdays, so I kept retrying and eventually got the Dashpaq+ fully updated. I also unplugged the battery cable on the Tahoe while I watched the entire UT/Alabama game. When I came back out, reconnect the battery and the Dashpaq+ and tried starting the Tahoe, I got the clicking noise when turning the key, following by wacky flashing lights. After that, attempting to start the Tahoe does nothing at all.

SO. First of all, any insight at all is greatly appreciated. But I also have a more specific question; what are the chances that I can correct this with an HP Tuner? I was thinking about getting one anyway.. an MPVI3 is 399 and then 2 credits for licensing will be 98, so 497 total. I new ACDelco ECU at Rockauto is only 97, minus the core charge. Then add on some extra to pay to have the new ECU programmed I assume..\

What do you think? How can I determine if my ECU is fried? Should I go ahead and get an HP Tuner or order a new ECU?

 

[Doubeleive]

First off, I want to mention that I'm a total rookie and have no idea what I'm doing.

I recently had my Tahoe regeared from 3.73 to 4.56. Since then the speedo has been off. I finally decided to take the time today to flash the ECU with my Superchips Dashpaq+ to fix it. I haven't used the Dashpaq in a few years so I guess I forgot the process. I was surprised when well over an hour had gone by and the flash still had not completed. Then, suddenly, the screen on the Dashpaq goes black. I waited another 10 minutes or so and then concluded that it must be done. So I turned the ignition off (it was in the "on" position with engine not running) and then tried to start the truck. It did not start. Instead, crazy lights flashing on the dash and a disturbing buzzing/crackling sound coming from the steering column area.

Now the Dashpaq no longer recognizes the Tahoe. It just restarts over and over again when I plug it in and turn the ignition on. Tahoe will not turn over and all electronics are acting really funky (windows won't move, security warning tone sounds randomly, interior dome lights do light up but really dim....)

Since the Dashpaq had been sitting on the shelf for a few years, I brought it inside and attempted to update the software on the Dashpaq itself. It failed several times and gave crazy error messages instructing me to call Superchips tech support, but it's Saturday and they only operate on weekdays, so I kept retrying and eventually got the Dashpaq+ fully updated. I also unplugged the battery cable on the Tahoe while I watched the entire UT/Alabama game. When I came back out, reconnect the battery and the Dashpaq+ and tried starting the Tahoe, I got the clicking noise when turning the key, following by wacky flashing lights. After that, attempting to start the Tahoe does nothing at all.

SO. First of all, any insight at all is greatly appreciated. But I also have a more specific question; what are the chances that I can correct this with an HP Tuner? I was thinking about getting one anyway.. an MPVI3 is 399 and then 2 credits for licensing will be 98, so 497 total. I new ACDelco ECU at Rockauto is only 97, minus the core charge. Then add on some extra to pay to have the new ECU programmed I assume..\

What do you think? How can I determine if my ECU is fried? Should I go ahead and get an HP Tuner or order a new ECU?

how those canned tuners work is it takes the software off the ecm/tcm/bcm and stores it on the device and puts there software on the modules. It sounds like yours got stuck some where in between and if you formatted it then your oem software is gone for sure. I would hold off and call them on Monday and see what tech support say's. My first guess is you may need a new bcm or a you can use a used one either way it will need to be programmed to your vin and then if the other modules are still not working those may need to be flashed also. I don't believe a hp tuner will be helpful in this case. you may end up needing a tech2 if you want to do the programming yourself, the gm software is online and there is a $40 charge from GM for 2 years of programming per vin number.
again I would wait and call them on Monday before doing anything else
if you have a aftermarket radio installed it could have been the reason the programming failed, if you do have one next time you go to program anything pull the radio fuse out first.

 

[Horsepowerguru]

If Hp tuners will still recognize your PCM still then it can be loaded with a factory tune back into it or if the OS is junk then you can load a NEW OS (operating system). However, the price would be a lot more than just getting a used PCM, assuming the PCM is bad. Pretty good chance you bricked it. Normally when youre writing and it get unplugged or loses power then the PCM bricks.

 

[Pilot]

Thanks for the feedback guys! I'll go ahead and wait until tomorrow when I can contact Superchips tech support and go from there.

 

[MassHoe04]

I do feel bad you are now in a real jam! With any luck, Dashpaq might be able to at least get you flashed back to some version of OEM programming. Maybe the Dashpaq makes a backup before it starts wiping the module. You might be able to do some kind of "restore" process to put the backup back in there. Fingers crossed!

Replacing with new/used modules and programming your VIN/mileage is still a possibility. If it were me, I don't know if I would want to try tackling that DIY on my own after something like this.

I'll be honest. In know it takes experience to get confidence, but I just don't have the cajones to mess with programming modules just yet. If one small step is missed, bad things can happen. I am not quite willing to go that far out of my own comfort zone...

Not on my daily driver. I don't have the time or money to deal with any extra complications.

Hopefully, you can do some kind of simple restore and get back to where you were.
Keep us posted. People here will make every effort to help you through this.

 

[Pilot]

Thanks for the support! I appreciate it very much. Luckily, my Tahoe is not my daily driver. I actually work from home so I don't even need a daily driver. So that takes some pressure off. I kinda knew that I was playing with fire ahead of time but I always have to learn things the hard way (often by breaking things and then having to fix them).

It's highly irritating to have my Tahoe out of commission, but I'll make the best of it and do some other mods that have been lying around in my garage. I'll keep this thread updated as I learn more on my ECU issue.

Thanks again!

I do feel bad you are now in a real jam! With any luck, Dashpaq might be able to at least get you flashed back to some version of OEM programming. Maybe the Dashpaq makes a backup before it starts wiping the module. You might be able to do some kind of "restore" process to put the backup back in there. Fingers crossed!

Replacing with new/used modules and programming your VIN/mileage is still a possibility. If it were me, I don't know if I would want to try tackling that DIY on my own after something like this.

I'll be honest. In know it takes experience to get confidence, but I just don't have the cajones to mess with programming modules just yet. If one small step is missed, bad things can happen. I am not quite willing to go that far out of my own comfort zone...

Not on my daily driver. I don't have the time or money to deal with any extra complications.

Hopefully, you can do some kind of simple restore and get back to where you were.
Keep us posted. People here will make every effort to help you through this.

 

[Pilot]

So I called Superchips tech support this afternoon. For some weird reason, my Tahoe is completely unresponsive today. As of yesterday, the electronics were all wacky but at least they were doing SOMETHING. Today, no power at all anywhere in the Tahoe. What's weird is that the Tahoe has been connected to a trickle charger since yesterday, and it's not a dead battery. And I tried reseating the battery terminal connections.. nothing.

So Superchips sent me some shipping labels and tomorrow I'll drop both my ECU and Dashpaq+ in the mail, overnight to Superchips. Hopefully they'll be able to either get me fixed up or at least let me know what I need to do. BTW I've been filming all of this–I'll be uploading some Youtube videos as soon as I have a chance to put them together.

 

[MassHoe04]

I guess you can't complain about customer service at Dashpaq... Can't ask for much more than that! Very impressive!!!

 

[ivin74]

So I called Superchips tech support this afternoon. For some weird reason, my Tahoe is completely unresponsive today. As of yesterday, the electronics were all wacky but at least they were doing SOMETHING. Today, no power at all anywhere in the Tahoe. What's weird is that the Tahoe has been connected to a trickle charger since yesterday, and it's not a dead battery. And I tried reseating the battery terminal connections.. nothing.

So Superchips sent me some shipping labels and tomorrow I'll drop both my ECU and Dashpaq+ in the mail, overnight to Superchips. Hopefully they'll be able to either get me fixed up or at least let me know what I need to do. BTW I've been filming all of this–I'll be uploading some Youtube videos as soon as I have a chance to put them together.

Any updates?

 

[Pilot]

Any updates?

YES! So...

So the reason the Tahoe became completely unresponsive is because the battery was somehow completely drained by this process, even though I had it on a charger through the night...

I shipped both my ECU and the Dashpaq+ overnight to Superchips with the label they provided. They received it the following morning, and by that afternoon they had re-flashed my ECU and dropped it back in the mail, overnight. I received it back the follow morning–less than 48 hours from when I shipped it. I put it back in my Tahoe and swapped my battery and now the Tahoe is back to normal.

I then installed all of the updates on the Dashpaq+ and tried again to flash my ECU to fix the speedo (on the charger the whole time this time). Dashpaq+ just keeps saying it can't communicate with my ECU because I have aftermarket equipment interfering with the signal. I do have a Viper Smart Start alarm installed; though I don't understand because that has been installed the whole time and never prevented me from flashing my ECU before.

Any thoughts? Think if I pull the fuse in the Viper system it will work? I had a shop install the Viper system so I don't know where the module is.. I'll need to find it to pull the fuse.

Anyway, next I'm going to focus on installing my new Mechman alternator and then probably the 4 note Cadillac horn. Also I just bought a PC laptop (I'm a Mac user) so I can use HP Tuners. That should allow me to flash the ECU for my e-fan upgrade that's also waiting in the garage.