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Author Topic: Bricked ECU cannot be recovered even with boot mode ME7.1.1 4Z7907551S  (Read 2448 times)
allroad_fan
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Hi, I'm new to this so if anyone could help fix my stupidity, I would highly appreciate it. I read every boot mode/bricked ecu post I could find here, but I still can't figure this out...
I have an Allroad 2.7t with the ME7.1.1 4Z7907551S ECU.
Everything was going fine until I accidentally (muscle memory I'm guessing) tried to crank the car without cycling the key, after reading the file from the ECU.
The car cranked but didn't start. I cycled the key numerous times, disconnected the battery/ECU, but it didn't work. Car would crank but wouldn't start.

I wasn't too worried about it since I expected that this could happen, so I had a Galletto 1260 cable. I removed the ecu and soldered a lead to the pin 24. Quadruple checked that it was the right pin, and checked multiple times with a multimeter to make sure there were no shorts. I put the ECU back into the car, using the original harness, ground disconnected, ignition on, shorted pin 24 to ground, connected the battery, disconnected the pin 24 ground after couple of seconds, and opened EOBD1260. It connected nicely and told me that it was in boot mode, I could read the ECU, read the file, and also write the file. I wrote the original file (both the one I read before and the original one from s4wiki) to the ecu countless time, following the instructions (turn off ignition for 10s after writing). I didn't have any errors displayed and everything looked OK.

Problem is the car was still cranking but not starting at all.

I tried different ways to do it in the car (different amount of time pin 24 grounded, key cycled, battery charger connected, jumped from another car, connected to external power supply...) nothing worked.

So, I thought I would try to do it on the bench. I followed the diagram and connected the necessary wires. Here is what I did:
-Power supply set to 13.5V
-All the wires are properly placed on the bread board and connected to the Galletto and the ecu (I have a bit of experience in this since I'm a robotics engineer)
-Checked the connections with a multimeter.
-Galletto cable and the ECU shared the same ground and VCC (I don't know if this is important info but I vaguely remember someone mentioning this somewhere)
-Put a switch on pin 3, for ignition.
-Connected to the computer and tested the setup, it read and wrote the file just fine. No errors.
-Connected the ECU to the car.

I tried to start the car again, it cranks but still doesn't start...

I'm not sure what I'm doing wrong because everything seems to go fine but it still doesn't work. What can I do to possibly fix this? Should I just accept that I may have fried my ECU? Would it work straight up if I bought an identical ECU elsewhere? Can I buy a different ME7.1.1 and flash the correct bin?

Any help would be appreciated. Thank you
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nyet
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http://nefariousmotorsports.com/forum/index.php?topic=981.msg53893#msg53893
« Last Edit: June 10, 2021, 01:49:38 AM by nyet » Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
allroad_fan
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Worked perfectly, thank you so much!

(I just wrote the 551R file instead of the 551S file and it started on the first crank!)
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