Trying to complete an e-fan swap on a 2004 Avalanche 5.3, using Windows 10 and a MPVI3
I was finally able to successfully read the ECU by removing the radio amp fuse and unchecking Use High Speed.
I activated the fans, set the temps, and tried to write the flash. Got an error: Control Unlocker: Timed Out
Now, my truck wont start.
Is the ECU bricked?? How to resolve this??
I tried disconnecting the battery for a few seconds and reconnecting. Truck still won't start. Does this mean the ECU is really bricked?
My device drivers are up to date. I also pulled all three radio fuses and the ABS fuse. Are there any other fuses I can try pulling?
Looks like I'm not driving to work tomorrow. Sux.
Thank you in advance for any insights or help.
Last edited by _Bowser_; 02-13-2023 at 01:39 AM.
I have had this happen on occasion. Things I have tried that worked are turning off ac/blower motor, I once worked on a 03 silverado that would only write with one door open but I don't remember which door(it was specific), turn headlights off, pulling fuses that are not needed one at a time until it will write. Twice I've needed to resort to a bench harness and both were 03 trucks.
try to connect your car battery to charger/jumper just to make sure you have 12v and uncheck high speed while writing, if it didn't work you might need to do it on bench harness.
How to turn off the ac/blower motor? Do you mean turning it off by pushing off on the climate control? Or pulling the fuse? Or?
I definitely have over 12v on the battery, checked with multimeter, but will connect a charger anyway to top it off.
Can I try writing while connected to the charger?
Potential of 5 fuses to remove.Originally Posted by _Bowser_
1. Radio
2. Radio Amp
3. Info
4. SEO B1
5. SEO Ign
These all contribute to Com errors
You should NOT use a charger when programming. Many cheap chargers send a heavy ripple that can and will effect programming. Almost all manufacturers now use a very specific charger for programming. It's not cheap. Best bet is to have a good fully charged battery connected with battery jumper cables to the vehicle battery. That will be more than enough.
Forgot to add. Yes it is possible you bricked the PCM. See if you can re-read the tune file and/or get a data stream out of it.
Ok, I've pulled all those fuses and will also pull all the fuses for interior lighting, cluster, climate control front/rear, aux power outlets, A/C blower.
I've also had the battery on a trickle charger, I'll wait until it automatically says "charged/tending" before trying again.
If I can't get a read during this disabled states is that certain confirmation that the PCM is bricked?
Thanks for your help.
Never like to say for certain as I am not doing the diagnostic but yes that means it is bricked. P59's can be "un-bricked".
How would one go about unbricking a P59?
Process of disassembling the PCM, shorting a solder joint while turning on Ign and programming a full write all at the same time. It has worked on about 15 I have done and 3 were permanently bricked and unfix-able. One I unbricked 4 separate times.
I've had the time outs a few times in the past. It was a bad USB cable. Might try getting a new one, see what happens before you get too far down a rabbit hole.
How did you know it was the USB cable?
I currently have my battery plugged into a trickle charger and waiting until it shows "Charged/Tending" before I attempt again, but realize that I need to "write entire" when attempting a recovery, so don't want to brick the PCM if it hasn't already been bricked.
Would any OBD/USB C cable work with the MPVI3 ?
Because it was consistently failing to write, or timed out. I'd say one out of 5 attempts to write, it would fail. That didn't stop until I replaced the cable with a new one. Now I'm not saying the cable is your issue, but it could be. Just saying that it could be a cheap and easy thing to rule out.
Also, I wouldn't do a write entire, unless you're doing something specific that requires it. If your just changing calibrations, write calibration is all you should be doing. Write entire is writing the entire operating system and setting into the ECM. Write calibration only changes the calibration and settings in the tune. When you do a write, it erases the calibration, not the OS. If you did a write entire, then it erased the whole operating system, and rewrites it with the change in calibration.
To unbrick a P59 you need to do a write entire
So, if my truck won't start after timing out during a write calibration, I need to recover by doing a write entire, correct?
Last edited by _Bowser_; 02-14-2023 at 01:57 AM.
Here is what I do if I have a time out.
1. Try again. if it fails
2. Try to communicate with the module. if it fails
3. Try a write entire. if it fails
4. Perform an "unbrick". if it fails
5. Get a replacement ECM/PCM
6. Build an off board programming setup
If the write calibration timed out, try a new USB cable, and attempt a write calibration again. If it is indeed bricked, it won't work and you'll have to take the steps to unbrick it as TheMechanic mentioned. With it timing out during a write calibration, it just means no calibration has been loaded, the operating system is still there. I suspect it's not bricked, but I really can't say for sure. Other people here have more experience with this than I do. I do know, that this has happened to me a few times with my 2014 Camaro e38. A new USB cable fixed it for me, but I can't say it will work for your specific situation.
E38 PCM bricking during programming = rare
P59 PCM bricking during programming = somewhat common.
Ahh ok, I didn't realize this was a common thing. Probably why OEMs recommend using a battery maintainer, not a charger, or trickle charger for programming. Them things are spendy though.
Reply With Quote