I flashed my PCM twice yesterday and both times it failed and left me with a "No Comm" error on the DIC. During each there were several automated re-attempts, going to low speed. After each failure I was left with a car that would crank but never start, also getting several TCS, Reduced Power, RDCM, LDCM, etc.. errors.

After several attempts I was able to correctly write a good flash, but this is some scary crap...

Any ideas?
-good batteries on car and laptop
-no USB serial converter
-over 500 previous successful writes...

 

What version of HPT?

 

Latest, 2.0.17

 

Man that is scary, Ive written over 200 times and now you got me thinking.

So what were your steps in recovery, just incase this happens to someone else. Did you do a full VCM write or just calibration?

I was also under the assumption that if you do a calibration write and it fails, its easy to recover because it does the erase first before flashing the new calibration file.

Dixit

 

I did not try a full VCM write. Each time it started restarting and failing over and over I would select abort and start the entire process over... I have no idea if this was the "right" way to work through this...

 

there are many things that can lead to this type of error..
usually one of he common problems is that the car battery is low voltage(not necessarily bad..but just not full charge on it, or it has been sitting for too long)
anything less than 11.5v DC is risky business...need to make sure you have more than that...It even says something in the HPT help files about it.

and the proper procedure is to just keep trying..I usually try to find a way to get a litte extra juice to the battery if something llike that happens

 

Car battery was showing 12.0 and laptop battery was at 95%... What has me concerned is this is the first time it has happened and it happened twice in 30 minutes...

 

So basically you just kept retrying the Calibration flash and it finally took one time? Man Im going to have to keep an eye on this stuff now.

As far as battery voltage, I guess Ive been running crazy risks, cause sometimes I would get ready to flash and my stereo is on and booming, I think the voltage gets as low a 11.5 when the bass hits but never had a problem yet. Ive done it with the door open, closed, radio running, ac running, all different ways people say not to do it and so far no problem.

Dixit

 

Hopefully pulling both PCM fuses and a key-on-off
cycle will get you your comms back. I have seen
this kind of thing twice - once with a too-slow
laptop (made me move up to a 266MHz monster)
and once when my first-batch EIO cable went out.
If you have an option handy like a USB serial to
replace the DB-9 connection you could see if the
built-in serial is gimped (mine got fried a while back
by undervoltage dropouts on a pulleyed truck,
freaked the cig lighter inverter and melted the
Wal-Mart cig-Y adaptor too).

 

Wait a minute??? When the VCM flash fails the error message says DO NOT un-hook the battery, in big bold letters...

 

12.0 v measured at the battery is a little low. 12.86 v is 100% charged