Could not write 2006 Grand Prix L32 ECM

As the title says, I went to write a new calibration to my 2006 Grand Prix and it failed every time no matter whether I selected write entire or write calibration. I also tried unchecking the write fast box (or whatever it says) and had no luck either. It would try to write and fail at different stages but it would always fail. Of course, since it had already started to write before it failed the ECM was basically dead and the car wouldn't run. One thing I did notice was when trying to write you could tell the operation was being interrupted as the dash, DIC, fuel pump, and other electronics would start and stop during the process instead of just stopping once when the write procedure started. I'm an ex GM tech and I have seen similar issues before on vehicles that could only be programmed using the offboard programming procedure. Those vehicles had issues with the write procedure being interrupted by too much activity going on on the data line. I was desperate to get the car running again because my wife has to take it out of town tomorrow so I figured I would try something. I figured that I would try to reduce the activity on the data line so I removed the SRS and ABS fuses from the underhood fuse block. The write was successful after doing that although it appeared to stumble a couple of times. I have read that some '06-07 3800 ECMs couldn't be flashed in old posts but was a little confused about whether that problem still existed or not. I figured that I would post my experience here to see if anyone else has experienced this same issue or not. The car is a 2006 Grand Prix GT with the L32 3800 and the OS is 12603217.

Can't say I've seen many people tuning the 06-07's because the support for them only came out like a year a ago or something.

Does the vehicle have an aftermarket radio at all?? I know that is a problem on the 04-05 cars, they just pull that fuse and it seems to work a lot better.

The car is all stock, no aftermarket electronics and no mods. I actually need to make some tweaks to the tune I have in it now but I'm too scared to try flashing it again until I get more info.

I know for sure that anyone using DHP and some with HPT use an off board setup to make sure nothing crazy happens.

Maybe support can help you more or someone else that has done one before.

I've only done the 97-03 body style and a GXP but they use a different computer.

I contacted support and they're looking into the issue. Other than my wife's car I've only flashed my 2000 GP. I've flashed it dozens of times and it always worked flawlessly. I've read the bin on several other vehicles and scanned them as well without any problems at all so I know it is a vehicle specific issue. Funny thing is that after support got back to me requesting more info I tried reflashing the car again in order to get them a screenshot of the error and the dang thing flashed twice without any problem. It acts a little quirky when doing a write entire but it does write successfully and doing a write calibration seems to be just as smooth as my car. It's odd indeed and now I'm more curious than anything else. As far as off board programming goes, it sure is a lot more reliable but buying the harnesses or making your own is costly and/or a PITA.

Try pulling out the radio fuse before even hooking up to the vehicle when writing to this perticular one in the future. No guarentee but this has helped many tuners out in the past with several different comms issues, mainly involving displays but all the better if it can help you out too. Good luck!

I'll definitely try pulling the radio fuse in the future. Support has my info log, the bin I was using, and my debug files and they are having an engineer look into it. Unfortunately, I couldn't get them a screenshot of the error so I don't know how much that will affect their findings. What has me really confused is that it writes successfully now. I know that I have a low post count and I'm relatively new to HPTuners, but I have reflashed countless cars over my career so performing the process properly is like a second nature to me. I've screwed up plenty of times when I was in a hurry or distracted or whatever, but I just can't recall anything that I did that would have caused the issue. Even though it may not appear that way, I'm really not worried about it that much because my car is fine and my equipment is fine and I have nothing but good things to say about the product or the company. I'm just the kind of person that has to know exactly what happened when something goes wrong.

It was most likely a communications issue with all that stuff chattering through and behind that radio. For whatever reason there wasn't as much communications interfering at the moment you preformed your successfull write. Very common around that year GM vehicle.