ssduane

iTrader: (3)

I've having some issues with my PCM, HP tuners or harness. HP tuners doesn't see my PCM and this happened during an abort Flash with my 01 PCM. I have a 98 PCM laying around, can I just hook up the 4 wires to the OBD II, 2,4,5 and 16, serial, grds and 12v or do I need to hook up all power supplies/grounds to the PCM to plug into HP Tuners?


PLan to plug laptop into truck tomorrow to see if it see's my truck, but wondering if I fried my 01 PCM?

socal

iTrader: (1)

look for a bench top cable, there like $100.

aknovaman

iTrader: (7)

Beware: 98 wires are different than 99-up wiring.

ssduane

iTrader: (3)

yup, thats why I have the 98, because I wasn't aware of the differences when I bought the setup so got a 01 PCM.

Did some more searching and looks like I need to hook up some blue connector pins, 12v and grnd to read. will try that this evening.

wait4me

iTrader: (10)

If you aborted during a full flash then the pcm will need to be torn apart and fixed. "flash chip pulled of or debug port used and flashed with a chip burner"

If it was during a partial flash, then the computer should still talk.

The 98 AND 99 up ecm can be read with the same bench flash tool. I do it every day. Pins im using are
60 ground
59 obd sig
19 ign
20 bat.

It also works for all 4 cly pcms and 6cly that use that same large blue connector that the ls1 computer is.

ssduane

iTrader: (3)

thanks for the info, my 12v to my OBDII port was bad, getting low voltage when I was writing to the PCM and HP Tuners lost connection and was trying to reconnect, think I wiped old program before starting to rewrite. Now it sees the interface but not the VCM, even hooked up my pocket scanner which shows no link.

will do a bench hook up to my 01 and 98 PCM and see what differences I get (more for personal knowledge gain) but I think the 01 PCM is bad now and might need repair like mentioned.

guess I can open it up and pull chip but think thats about all I can do.

wait4me

iTrader: (10)

I fix them for 30 bucks.

ssduane

iTrader: (3)

you might be getting a call then.

ssduane

iTrader: (3)

Bench tested my 98 PCM, HPT reads fine, 01 PCM, nothing, guess I need repair/replacement.

wait4me

iTrader: (10)

Yeah it sounds like a FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF'd up chip.. lol Pun intended...

ssduane

iTrader: (3)

yup, found one flashed for 40 bucks shipped, waiting for it to come in.

Thanks for the info on bench testing, on a side note, Pin 60 on 98's is PCM ground, 99 and up its TPS ground, does this matter or since its a ground it grounds the whole thing?

wait4me

iTrader: (10)

Ive tuned over 20,000 of those type of ecms with that pinout on that harness bench from the counter, so I would say it works just fine.

boostit5.3

iTrader: (3)

i had a similar thing happen to my car, but my laptop crashed while i was uploading a tune. it kept giving me errors and saying the ecm wasnt there. i unhooked the battery, hooked it back up and luckily the cars ecm took the tune.

wait4me

iTrader: (10)

That only depends on if you do a full flash or a partial flash. If you do a full flash on the 1998-2005 ls1 style ecm, it does not contain the information for it to work anymore if there is a failure before it is done. It is basically brain dead. However, if you are just doing a partial flash, where it is only changing the calibration area, the operating system is still intact allowing you to flash again and put in valid data in the missing area.

It is a Set thing in stone how it works. There are no maybes or not..
The only thing that would save you on a full flash failure is to NEVER remove power to the pcm if there was a failed right, and DO NOT cycle the ignition. That is the only point of recovery, but then again, it also depends on what software you are using. On EFIlive, I can pull the cable while full flashing, and it would recover as long as I finish a flash before pulling power. This is not recommended to try, however, it does fix itself. The bootloader stays in memory waiting for instructions.

James@ShorTuning

As mentioned never pull the battery or main power to the PCM if a flash fails. If this is the case you basically brick a PCM. I just purchased efilive v2(used cable) so Ill familiarize myself with it over the next bit but have used HPTuners for years now. With it you can cycle the key on the newer 99-up PCM's and still recover them however the 98's are about pure junk much like the LT1 PCM's.

I'd like a little more info on recovery as I have a few bricked PCM's from over the years and have extensive chipping knowledge from my earlier years chipping Honda and obd1 GM ECU's.

James@ShorTuning

Think you meant pin 58 for OBD signal... I'm actually in the process of building a harness myself. Gotta make some E40, E38 and E67 bench harnesses as well... Am gonna make the diagnostic port plug into the PCM/ECM plug so I can mount my OBD2 port to a bench and easily plug a weatherpack harness into the adapter for whatever computer I'm working on.

wait4me

iTrader: (10)

Please erase this post. It is NOT pin 58. Use pin 59 as stated. Thanks.

wait4me

iTrader: (10)

James, if you open up your EFIlive software and hit the help button, the go to the tutorial tab, there is one in there called bench harness It will walk you step by step for all the harness stuff you need, including pictures.

James@ShorTuning

Thats what I was going from which is why I asked... My pinout of the 99-03 PCM's shows Blue connector Pin 58 as does the tutorial... Here is a screenshot.

dodson55

iTrader: (18)

my bench harness uses blue pin 58 and works just fine blue pin 59 is used to link the pcm to the bcm i beleive and is not needed for a bench harness