Just installed HPT. Can't read VCM. Help!

[Tommy Tucker]

Hi All,
This is a second post on the board for this question. I've also put it in the 'help' section. But I need as much info as possible.
I'm in the UK so I won't be able to visit this post again for a good few hours. I hope someone can help. I know this problem has come up before but I can't find the answer.
I have a LS1 GM crate motor and VCM.
I've just installed my HPT 2.1.10 and am unable to even read the VCM.
I get the 'verify cable is connected and key is in the run position.' error message. The interface has the power LED illuminated and a slowly flashing 'busy' LED, so that looks ok?
Is there a way to rectify this?
I've uninstalled and reinstalled it but no luck.
This is very urgent.
Any help appreciated.
Tom.

[Shifted]

Might be a stupid question, but are you turning the key to the On position, engine NOT running?

[kabbott]

Does the scanner work?
power to the OBDII port?
Email Support they are usually pretty quick responding.

[Casey]

Sounds like there is something wrong with the data line on the OBDII bus.
Is this an aftermarket wiring harness?

On a side note, we dont support the LS1 GM crate motor VCM. You will have to do a write entire with a vehicle calibration. Then you can proceed with tuning the motor using that VCM.

-Ken

[Tommy Tucker]

Thankyou Ken.
I will check the OBD-2 connection.
So does this mean that I should copy a stock bin file from another VCM, write entire file to my VCM and then I can read and scan that file?
Can I pick up a stock bin file from the shared list by Hoirst?

I don't quite understand why the crate motor VCM is not supported? I would have thought that it's just another GM LS1 VCM??? Oh well.

Tom.

[Tommy Tucker]

I've checked the OBD2 port on the loom with a multi-meter and it's connected to the correct VCM pin and has a good connection.
Both ground pins (4 and 5) are connected and show 13v when ground to the chassis. The battery power (16) is also at 13v.
Still getting exactly the same result as above.

[Casey]

I've checked the OBD2 port on the loom with a multi-meter and it's connected to the correct VCM pin and has a good connection.
Both ground pins (4 and 5) are connected and show 13v when ground to the chassis. The battery power (16) is also at 13v.
Still getting exactly the same result as above.

The interface has to pass a QA test of talking to a simulated vehicle, so we are reasonably certain the interface is ok. Please try an scan another vehicle to test the data line functionality.

Other than that it still sounds like the data bus on your vehicle has a problem (shorted to ground or not connected). It will be Pin 2 of the OBDII connector to pin 58 of the VCM Blue connector.

[RomansDesigns]

I was just able to read a GMPP Crate Motor pcm, however I still can't edit the file. The crate motors use a vin of "LS*1*AUTO*VERS*01" (At least this one did) my mpvi wouldn't even recognise the pcm. Keith has it worked out using a beta to read the file. Now it appears that the checksum is disabled in the PCM so I emailed it to Keith. I think now, I could if I needed to rewrite the whole thing. I'd rather be able to at least see what GMPP did to the file though! I previously just installed another 98 PCM and tuned that for the guy.

[RomansDesigns]

Just a note, it's not your interface. I am now able to see and read the 98 GMPP PCM with the beta that Keith sent me. Without that BETA the interface won't even see the GMPP PCM. My tech2 was able to read the pn of the software (pn of the software is 12480112.) HP Tuners will scan it. See if your scanner scans it! Once you get the beta, you will probably need to download another 98 file from HORIST's site and just overwrite it and start over. If you need a good base file, let me know.
Mark

[Keith@HPTuners]

Well, it was able to locate the PCM it just wasn't sure what PCM it was.

The VCM Suite info log uses the simplest form of communication to locate a VCM. That is the sure fire way to tell if your laptop can talk all the way through to the PCM itself.

Even if the software doesn't recognize the PCM data, the VCM Suite info should still show a VIN and other data that it can grab.

[Tommy Tucker]

Hi All,
Some progress made.
I have been able to scan the vcm while it was running and see the basic data (rpm, MAP, knock, spark advance, etc.).
So can I now assume that the HPT interface is talking to the pcm and the link to the laptop from the OBD2 port is also ok?
Please could anyone advise on the next steps to take?
Thanks.

[MIZZLE187]

A similar thing happened to me when I first tried to read my tune in my 03' Silverado. It was a result of me forgetting to pull my radio fuse. It read fine after that. Hope you figure it out!

[TIM Z]

What does pulling the radio fuse do? I am trying to read the computer in my fathers 99 chevy suburban but i get the same message, make sure key is on and cable is connected? What am i doing wrong? -Thanks for any help you can give.

[EC_Tune]

Some aftermarket radios put a "thumbsucker" in the line so the other modules in the vehicle think the factory radio is still there.

These devices won't shut up most of the time and will cause data errors on the bus when you try to read or write as they interrupt communications with a message that basically says "I'm HERE and I want to TALK if you'll just LISTEN!"

EC

[kamikazematt]

sorry to dig up an old thread. i have a guy with one of these gmpp ecms, was there anything updated with these in the later HPT software? can i edit them or do i need to do a write entire and start with a 98 file?

[Bill@HPTuners]

Pretty sure we don't support the old GMPP pcm files I believe they disabled the checksums.

[kamikazematt]

is it possible to do a write entire then with a stock 98 file to get the computer to work or is it basically a locked computer?

[Bill@HPTuners]

The computers aren't locked, you could probably do a write entire to fix it.

[Wolf]

The computers aren't locked, you could probably do a write entire to fix it.

So can anyone confirm this actually works? I have a customer with the same GMPP PCM in a street rod, and he's considering just putting a used 411 PCM in there to get around this problem.

[Bill@HPTuners]

if I'm not mistaken the old GMPP pcms being referred to in this thread were based off the same 97/98 LS1 architecture meaning a 411 pcm is completely different internally and wiring so simply "putting in a used 411" isn't quite that simple.