DHP pcm write fail

Shiwnath · 08-12-2012, 04:23 PM

I tried flashing a new calibration to the PCM and midway though it failed.... I tried auto recovering it with no success... I tried a full write and still nothing... If i try to read the VIN, it'll make an attempt and be partially successful with initial response but it wont actually read the VIN... My Alero wont start now... Is there anything I can do to fix this?

01GrandAm · 08-12-2012, 07:20 PM

Try doing a Full Write...

If that doesn't work, your only hope may be to recover it using an off board harness.

Shiwnath · 08-12-2012, 07:25 PM

Quote:

Originally Posted by 01GrandAm

Try doing a Full Write...

If that doesn't work, your only hope may be to recover it using an off board harness.

Yeah sadly i couldnt get it to do a Full write... I've already pulled PCM.. Looks like a replacement is my only option... I'm scared that it'll happen again if I get a new PCM... I had no idea the 12V AUX port worked off the same source as the OBD2 port and I had my laptop plugged in using an inverter and i think this may have caused an issue.

xXManwhoreXx · 08-12-2012, 08:13 PM

Put it in a loop maybe and burnt it out

WhiteV6 · 08-12-2012, 08:25 PM

HPTuners hate having the laptop plugged into a converter while hooked up to the car. I have no idea if DHP have the same problem but I have to run on battery power only in the car. If you need a PCM flashed with your VIN, I have computers here.

Shiwnath · 08-12-2012, 08:54 PM

Quote:

Originally Posted by WhiteV6

HPTuners hate having the laptop plugged into a converter while hooked up to the car. I have no idea if DHP have the same problem but I have to run on battery power only in the car. If you need a PCM flashed with your VIN, I have computers here.

The laptop that came with my DHP doesnt hold a battery charge for long at all so i have to have it plugged in or it dies within 10-15 minutes.. Sadly DHP uses a serial port so I have to wait until my keyspan adapter comes so I can use my laptop... Ugh so frustrating.

Thanks for the offer Ben, but I can't wait too long for a PCM... Probably a dumb idea to mess around with my daily driver on a sunday though

.. I can get a local PCM from a junkyard for $40.

AleroB888 · 08-12-2012, 09:50 PM

Quote:

Originally Posted by WhiteV6

HPTuners hate having the laptop plugged into a converter while hooked up to the car. I have no idea if DHP have the same problem but I have to run on battery power only in the car. If you need a PCM flashed with your VIN, I have computers here.

I saw the disclaimer on the HP Tuners forum about the inverters for some time now, but before that I used the Radio Shack models for years with no problems, and still do on occasion. I don't start the car with it plugged into the laptop, though. Any more, I make sure I have the laptop battery fully charged before doing a reflash, especially a "write entire."

In the early years with HP tuners, I had to use a USB adapter, and that caused problems. One time a reflash went wrong, and when I started the car, it sounded like the tranny had mechanical damage (wtf!) I did another rewrite and it went back to normal.

I now let the car sit for about 20 seconds after key-on, even fasten the seat belt, make sure the PCM settles, then do the reflash. But it's always scary.

WhiteV6 · 08-12-2012, 11:13 PM

I had to send my nearly new unit back a week after I got it because i was using an inverter. Nothing came with it, you have to read a forum to know that. You shouldn't have the car hooked up to a battery charger at the same time either.

Shiwnath · 08-13-2012, 10:13 AM

Okay so I got a PCM from a 2000 Malibu with the same service number... Does anyone know if i have to do the security relearn BEFORE i can Read/write from the PCM?

AleroB888 · 08-13-2012, 12:29 PM

Quote:

Originally Posted by Shiwnath

Okay so I got a PCM from a 2000 Malibu with the same service number... Does anyone know if i have to do the security relearn BEFORE i can Read/write from the PCM?

Does the car start with the new PCM in it?

tw0123 · 08-13-2012, 02:06 PM

Just cuz it starts might not be the answer... i got a pcm from a cavalier for my coupe with the same numbers and it started... when i hit the gas it died though... fuel trims etc were way off

Shiwnath · 08-13-2012, 04:02 PM

With the Malibu PCM, it started and drove semi ok but the trip meter wouldn't increase as i drove and the fuel gauge didn't register a proper reading... I ended up having to take the Malibu PCM back and had to find a 2000 Alero PCM elsewhere which I should have done to begin with. I'm better off with the Alero PCM anyways because it's properly calibrated for the 3400 + 4T45E.

The car is properly running again, but my DHP refuses to read/write to the PCM BUT I can still data log and read/clear DTCs which is odd...I think it's partially fried. So I paid $500 For DHP only to have to return to stock calibration. I'm hoping that when my keyspan adapter arrives that it might work with my other laptop... I'm just hoping I fried the serial port on the old laptop and not the actual DHP interface itself. It's been a crappy experience but atleast my car runs again and I've learnt from this experience... I think I'm done modding for this year lol.

Rexter9x · 08-14-2012, 05:48 PM

Yea, that doesnt sound like a pleasant experiance. But at least the car is running again. Hopefully its just the laptop being the issue.