2001 Corvette C5 Auto - No crank / No start after reading file.

[adamlewis82]

Hi all,

I'm at a loss at the moment and really in need of some expert help...I've raised support with HPT but have done the things they suggested but they're not sure whats happening either, just hoping someone must have seen this before?

To start with, I've just diff swapped my 2001 auto vette, I wanted to use HP tuners to chance my final drive and ammend the shift points...once I'd done the swap the car was running fine, shift points weren't too bad but I wanted the quicker and improve general drivability so ordered HP tuners MPVI2 and the 2 credits needed.

Followed all instructions and registered the device and sync'd with the car, no problems at all...used the scanner app to make sure everything is reading fine and all looked ok.

Then used the editor app to read the current map and back it up a few times like i've seen suggested...id made sure the battery was fully charged when I did this and it read fine, went through the cleaning up stage and saved.

Thought nothing of it, closed the program and shut the ignition off and unplugged....when I've gone to start the car I get nothing, everything powers up fine but as soon as I crank it, it just drops all power just like when I had the imobiliser lock me out 6months ago, so that was bypassed with the resistor mod then and its been fine. (i've tested this since and the resistance it still matches the key)

The security light has always flashed before plugging it in and goes off when I start it, but now i'm not seeing any security, no flashing or illumination.


I've since tried to edit the stock file and remove vats and save it as hpt suggested and upload that but again made no difference.

I've checked the number 14 crank fuse, and other fuses around there and under bonnet and all looks fine, i've even tried to ground the yellow/black wire from the anti theft relay to the body as this was suggested when vats had been removed with HPT.


I just don't see how plugging the box in to read the file has done so much damage, it was working perfectly that afternoon.

Is anyone able to have a look at my tune file and see whats got messed up along the way, or have any other suggestions on where to look or what to try? I just want to get it running and enjoy it...esp as missed a car show I was booked in for that night it decided not to start.

I'm also using the beta version too like HP suggested.


Many thanks in advance

Adam

[blindsquirrel]

Do you get a lit-up Check Engine light at key-on? Will the scanner still connect and display live data?

Did you write the 'NO VATS' file to the car or did it fail?

[adamlewis82]

Yeah the check engine light stays lit at key on, and the scanner still connects.... I've wrote the no vats file also and yeah no fails, all say completed.

Anything I can view on live data to pinpoint?

I've got no fault codes stored in the car on on board diag, or with handheld scanner or hp scanner.

[2xLS1]

Have you tried just disconnecting the neg battery terminal for a few minutes? And using a beta version for a 2001 vehicle is completely unnecessary. Stable version on a vehicle that old would be fine. MPVI2s seem to have more problems with P01 and P59s than the MPVI1 ever had And I don't understand what you meant by this. <went through the cleaning up stage>

[blindsquirrel]

Battery voltage with key in 'crank' position? Do the headlights/other electrical loads drop out or only the cluster? Because what you're describing sounds a lot like what you get with a loose battery cable - works fine until there's a real load, then goes open circuit.

It did this before you ever tried to write ANY file back to the car, right?

[blindsquirrel]

There will be good data on the security status junk in a Tech2, but as that's a system spread across non-PCM modules you aren't going to get there with the HPT.

[adamlewis82]

Yeah, have tried disconnecting the neg for 30 mins, then both, then touching them together for about a minute.

Not sure why they recommended the beta version, did think it was strange just thought they may have more access to the data.

That's a shame then, wish I bought the older version now hearing that then.

Re: cleaning up stage.... Once it's writen the file, it says cleaning up, then primes the fuel pump and makes some other click noises then says completed.

[adamlewis82]

@blindsquiral - Battery voltage is around 12.6 ish vees, and I've just been out to test it now with the headlights on and when cranked to on position the cluster shuts down but the headlights stay bright, they don't even flicker.... Terminals are definitely tight and clean also.

And yeah, this problem has only come since reading the car to back up the file, and still here once trying to send that file back hoping to clear it, the same with vats removed.

[blindsquirrel]

Do another read, compare that file to the others you have been working with. It should not have done any 'cleaning up...' after doing a read.

[adamlewis82]

Do another read, compare that file to the others you have been working with. It should not have done any 'cleaning up...' after doing a read.

Just done another read of the car and its done exactly the same, reads its fine and says cleaning up once done, primes the fuel pump and clicks a few relays...i've attached the file and also a log a ran whilst plugged in and trying to crank, not sure if it shows anything? I cant really see anything but I don't know what im looking for really.

I've also tried testing the anti theft relay for volatage across the purple and red wires and got 13v and then as soon as it cranks relay clicks and voltage drops to zero, hence why its not allowing it to start and send power to the starter/rest of system....I've also tried jumping those to bypass it but no luck....still no error codes showing up.

[blindsquirrel]

The majority of the theft deterrent is in the BCM. The PCM only receives a go/nogo signal, it doesn't have the ability to know why the BCM says what it says. Without a scantool that can read the VTD status in the BCM there's not much you can do with only the poke-and-hope method.

The resistor bypass for the key pellet only fools the BCM into thinking it's got a valid key (and that those damn annoying skinny little wires in the column aren't broken), otherwise the VTD still does everything the same as before the bypass. It's not really disabled, it just thinks it's *always* reading a valid key.

When you wrote the NO VATS file, you used 'write entire', correct?

Even though it should technically be disabled, I'd try doing the 30-minute relearn thingie anyway as a last ditch attempt before giving up and handing it off to someone with full-system scan tool ability.

[adamlewis82]

This vats thing sounds mega complex, I never realised how in depth this could ever be, I really appreciate you taking the time to reply and help me out.

With regards to writing the no vats file, I'll only ever wrote the write file or write vats... I've never done the entire as its says its brickable so was scared to do that.

And yeah I'm pretty much at that point now of handing it over, although living in the UK having a specialist in diag is gonna be rare.

Sorry for my ignorance, what's the 30mins re learn thing?? Not seen about that yet?

Thank you 🙏

[blindsquirrel]

Programming Theft Deterrent System Components

Important:
? The body control module (BCM) must be programmed with the proper RPO configurations before performing learn procedures. Refer to Body Control Module (BCM) Programming/RPO Configuration .
? If replacing the BCM with a GM Service Parts Operations (SPO) replacement part, the module will learn the passkey data code immediately. The existing PCM however, must learn the new fuel continue password when the BCM is replaced.
? If replacing a PCM with a GM Service Parts Operations (SPO) replacement part, after programming, these modules will learn the incoming fuel continue password immediately upon receipt of a password message. Once a password message is received, and a password is learned, a learn procedure must be performed to change this password again. A PCM which has been previously installed in another vehicle will have learned the other vehicle's fuel continue password and will require a learn procedure after programming to learn the current vehicle's password.

Conditions

Use these procedures after replacing:
? BCM
? PCM

10 Minute Learn Procedure
Tools Required
? Tech 2
? Techline terminal with current SPS (Service Programming System) software

Connect the Tech 2 to the vehicle.
Select "Request Information" under "Service Programming".
Disconnect the Tech 2 from the vehicle and connect it to a Techline terminal.
On the Techline terminal, select "Theft Module Re-Learn" under "Service Programming".
Disconnect the Tech 2 from the Techline terminal and connect it to the vehicle.
Turn ON the ignition, with the engine OFF.
Select "VTD Re-Learn" under "Service Programming".
Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF (the vehicle is now ready to relearn the password on the next ignition switch transition from OFF to CRANK).
Turn OFF the ignition, and wait 5 seconds.
Start the engine (the vehicle has now learned the password).
With the Tech 2 (scan tool), clear any DTCs.


30 Minute Learn Procedure

Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the password on the next ignition switch transition from OFF to CRANK).

Important: The vehicle learns the password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
Start the engine (the vehicle has now learned the password).
With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).

[adamlewis82]

Thanks for posting all that mate, my only concern is I'm not getting a security light at all on the dash, that's why I was thinking this whole things strange... It always used to flash but I'm not get anything anymore... So the relearn thing I could try just by waiting around 10mins but not sure.

[blindsquirrel]

You need to look at BCM data for this. That means someone with a Tech2 or similar that can access more than just the PCM in isolation. The BCM makes all the VTD decisions, BCM controls the security light over class2 to the cluster, the BCM has data PIDs in a dedicated Security section that can't be looked at without a tool that can read BCM data.

[adamlewis82]

Well slight bit of progress albeit slight, wrote the complete file today instead, and that's reset all the security thing, as now I'm getting the security flash and soon as ignition is on it goes off as it should.

Also getting 12v out of the the purple wire at crank and 12v out of the red wire all the time as it should, however I'm still getting no crank so somthing is still stopping it.

I've also tried bridging the starter with a screwdriver to engage the starter solenoid and even that didn't crank so I can only pressume the starter has miraculously died over night after the first read?