HP tuning reflash requires battery unplugged to start

brad65ford · 02-20-2022, 07:07 PM

Hi guys, for some reason every time I flash a new file to my 18 zl1 it will not start correctly, runs rough and then goes into power reduced fault. Only way around this for it to start correctly is by unplug the battery. Is this normal or is there some steps I'm not doing correctly to avoid unplugging the battery ever time I reflash a revised file? Any help would be appreciated.

KingLT1 · 02-20-2022, 07:39 PM

Before flashing with HPt, I always put the car in accessory mode first by holding start button with foot off brake for about 5 seconds.

Flash controllers with HPt...

Power the system off by pressing the start button once with foot off the brake.

Get back into Accessory mode same way as step 1.

Start engine.

JSH · 02-20-2022, 07:48 PM

I always must repeat your step 1 due to the crank cam sensor Non start.

Quote:

Originally Posted by KingLT1

Before flashing with HPt, I always put the car in accessory mode first by holding start button with foot off brake for about 5 seconds.

Flash controllers with HPt...

Power the system off by pressing the start button once with foot off the brake.

Get back into Accessory mode same way as step 1.

Start engine.

Trochoidal · 02-20-2022, 08:12 PM

Quote:

Originally Posted by KingLT1

Before flashing with HPt, I always put the car in accessory mode first by holding start button with foot off brake for about 5 seconds.

Flash controllers with HPt...

Power the system off by pressing the start button once with foot off the brake.

Get back into Accessory mode same way as step 1.

Start engine.

This is how I do it too and the car starts fine each time.

brad65ford · 02-21-2022, 08:39 AM

Quote:

Originally Posted by KingLT1

Before flashing with HPt, I always put the car in accessory mode first by holding start button with foot off brake for about 5 seconds.

Flash controllers with HPt...

Power the system off by pressing the start button once with foot off the brake.

Get back into Accessory mode same way as step 1.

Start engine.

Thank you, I tried this today we another revision from my tuner. No dice unless I'm doing it incorrectly. When you say foot on the floor and press the start and hold it starts. Not sure if there is away around this?

PROMETHEUS · 02-21-2022, 10:10 AM

WOW.....all of this BS to get the car to start because it has been tuned.

brad65ford · 02-21-2022, 10:19 AM

Quote:

Originally Posted by PROMETHEUS

WOW.....all of this BS to get the car to start because it has been tuned.

BS... I guess. From what it seems there is a process in which to shut down properly after flashed, but I don't' know it and that is why I'm asking.

The way around it is disconnect battery and its fine. IMHO that isn't a lot bs to do, just 10mm wrench and your good. You comment and concerned response makes we wonder if you've ever modified cars prior. I as many others have been down that rabbit hole so many times over with tuning/modifying cars prior. This is just a miniscule thing in caparison to many other things that could happen.

JSH · 02-21-2022, 10:20 AM

Quote:

Originally Posted by brad65ford

Thank you, I tried this today we another revision from my tuner. No dice unless I'm doing it incorrectly. When you say foot on the floor and press the start and hold it starts. Not sure if there is away around this?

I just did this yesterday so you'd think I could write it here:

1. Turn on laptop and plug into OBDII,
2. With foot OFF brake, put car in accessory mode by pushing the start button for a second or two, release, then hold it down until its light turns green, a bunch of dash lights will appear and things will beep,
3. Open HPT and connect to car,
4. Close scanner and open Editor,
5. Select the tune to load and write the file to the car,
6. Exit HPT and turn off the ignition.
7. Put foot on brake and push ignition. It will go "clunk." [mine does anyway because of cam sync] Take foot off brake then back on, push start, vroom.

brad65ford · 02-21-2022, 10:25 AM

Quote:

Originally Posted by JSH

I just did this yesterday so you'd think I could write it here:

1. Turn on laptop and plug into OBDII,
2. With foot OFF brake, put car in accessory mode by pushing the start button for a second or two, release, then hold it down until its light turns green,
3. Open HPT and connect to car,
4. Close scanner and open Editor,
5. Select the tune to load and write the file to the car,
6. Exit HPT and turn off the ignition.
7. Put foot on brake and push ignition. It will go "clunk." Take foot off brake then back on, push start, vroom.

Awesome will try this and report back. Knew there had to be a simple process in successful flash with out having to unplug battery. TY

LiqTenExp · 02-21-2022, 10:27 AM

Quote:

Originally Posted by JSH

I just did this yesterday so you'd think I could write it here:

1. Turn on laptop and plug into OBDII,
2. With foot OFF brake, put car in accessory mode by pushing the start button for a second or two, release, then hold it down until its light turns green,
3. Open HPT and connect to car,
4. Close scanner and open Editor,
5. Select the tune to load and write the file to the car,
6. Exit HPT and turn off the ignition.
7. Put foot on brake and push ignition. It will go "clunk." Take foot off brake then back on, push start, vroom.

You don't need to open VCM Scanner before opening VCM Editor.

Note, car will appear to reset after loading a file but it still needs you to turn off power and then turn car back on and start (detail of step 6 and 7 above).

JSH · 02-21-2022, 10:35 AM

Quote:

Originally Posted by LiqTenExp

You don't need to open VCM Scanner before opening VCM Editor.

Agreed, but close it if it's already open or mine won't write a file

KingLT1 · 02-21-2022, 11:39 AM

Quote:

Originally Posted by PROMETHEUS

WOW.....all of this BS to get the car to start because it has been tuned.

No...that is just the procedure for first start after flashing ECU. After that proceed as normal.

Quote:

Originally Posted by JSH

Agreed, but close it if it's already open or mine won't write a file

That is because VCM is still connected. All you have to do is disconnect but still can leave the program open.

You can avoid the clunk of you go back into Accessory mode before starting.

Camaro1973 · 02-21-2022, 12:53 PM

Uhhh why make this so difficult ? Put in accessory mode, flash car. Push start button to turn offf. Push start button to cycle power back to on, then start the car.

You don’t need to do any of this other nonsense. It just needs a power cycle after.

MartinLe · 02-21-2022, 01:57 PM

1) with ignition off, connect HP Tuner to OBD port.
2) open editor and select file to flash (I always make sure nothing is running on
the computer except the editor)
3) push start button - with foot off brake - until all dash lights come on
4) select write calibration
5) after writing process is done, turn off ignition for 10 seconds
6) turn ignition on for 10 seconds -do not start car
7) turn ignition off for 10 seconds
8) start car.

With this sequence, I have never had any problems.

02-20-2022, 07:07 PM	#1
brad65ford Drives: 2018 Zl1 Camaro Join Date: Jan 2022 Location: FL Posts: 28	HP tuning reflash requires battery unplugged to start Hi guys, for some reason every time I flash a new file to my 18 zl1 it will not start correctly, runs rough and then goes into power reduced fault. Only way around this for it to start correctly is by unplug the battery. Is this normal or is there some steps I'm not doing correctly to avoid unplugging the battery ever time I reflash a revised file? Any help would be appreciated.

02-20-2022, 07:39 PM	#2
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,838	Before flashing with HPt, I always put the car in accessory mode first by holding start button with foot off brake for about 5 seconds. Flash controllers with HPt... Power the system off by pressing the start button once with foot off the brake. Get back into Accessory mode same way as step 1. Start engine. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

02-21-2022, 12:53 PM	#13
Camaro1973 Drives: 2019 ZL1 Join Date: Mar 2019 Location: NJ Posts: 1,534	Uhhh why make this so difficult ? Put in accessory mode, flash car. Push start button to turn offf. Push start button to cycle power back to on, then start the car. You don’t need to do any of this other nonsense. It just needs a power cycle after. __________________ 928rwhp - 93 \| 1040rwhp/898rwrq - E65 SAE LME 377 LT4 Short Block \| Magnuson 2650 80mm upper w/13% lower (9.06) \| DSX Lid & Valve Covers \| CSP Custom Cam w/32% fuel lobe \| CID Heads \| NW 103mm TB \| Roto Fab Big Gulp \| CSP 2" Headers w/Green GESI Gen 2 Cats \| Borla 3" Full Cat Back w/ S-Type\| Mighty Mouse Wild Catch Can\| Custom Holley Low side Fuel system\| TooHigh PSI Port Injection w/Holley Controller \| Forced Inductions Interchiller w/2 gallon fender tank \| TK Performance built 10L90

02-21-2022, 01:57 PM	#14
MartinLe Drives: 2017 Chevrolet Camaro ZL1 M6 Join Date: Jul 2020 Location: OR Posts: 479	1) with ignition off, connect HP Tuner to OBD port. 2) open editor and select file to flash (I always make sure nothing is running on the computer except the editor) 3) push start button - with foot off brake - until all dash lights come on 4) select write calibration 5) after writing process is done, turn off ignition for 10 seconds 6) turn ignition on for 10 seconds -do not start car 7) turn ignition off for 10 seconds 8) start car. With this sequence, I have never had any problems. __________________ JRE Terminator Rough Idle Cam Magnuson 2650 - 15% lower, 90mm upper FIC+30% DSX Flex fuel/Low side NW 103mm TB/Roto-Fab CAI Monster S Series Elite E2-X 2" TSP LT's BMR:BK063, BK060,TCA061, UTCA060, UTCA063 Weld Beadlocks/17" NT5R2

02-21-2022, 10:10 AM	#6
PROMETHEUS Drives: 2019 ZL-1, Shadow Gray, Sold Join Date: Jan 2019 Location: Fredericksburg, VA Posts: 1,390	WOW.....all of this BS to get the car to start because it has been tuned.

User Name		Remember Me?
Password