E38 issues to avoid, VSS issues and throttle TAC issues, incompatibility

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04-30-2015
trbo355

E38 issues to avoid, VSS issues and throttle TAC issues, incompatibility

I thought i would share some E38 PCM info that may or may not have been covered already to save the next guy the misery i went thru with a customers car. We retrofitted an LS3 into a 66 nova and based the system off of 2010 camaro components with a 2010 corvette gas pedal all supplied from the oufit that sells me custom wiring harnesses.

Its been covered before but do NOT flash a 2007-2008 E38 with a 2009-2010 OP system or it will corrupt the PCM and render it useless. NVRAM corrupts???

Avoid reflashing a PCM with a 2010 Camaro OP system unless the PCM actually started life as 2010 camaro. It has its own P/N on the E38 and is the bastard child of the E38's. Flashing a similar year E38 with 2010 camaro results in unfixable throttle issues and a dead pedal after about 5 jabs and plugging in TAC calibrations from any other model will NOT solve the issue. Avoid 2010 camaro OP system on a non stock reflash at all costs.

On my 2010 camaro based harness, any OP system besides 2010 corvette or camaro would result in a VSS reading of 158 mph and was also unfixable. The solution to my dilemma was to follow the recommendation of a local GM tech and flash my 2010 silverado based PCM to 2010 corvette OP system and it all worked flawless.

Even attempting to rewrite the throttle axis tables to remove the rather lazy corvette programming resulted in throttle blowout so to avoid headaches, use the TAC programming the OP system came with. Im sure there is more to this story that other can feel free to add to this info but this is a good start to understanding the damn E38.
04-30-2015
granatl

Over a year ago, my wiring harness melted on a header and shorted out the E38 PCM. I bought a refurb from GM that had like a 2008 Saturn OS on it. I put my Camaro HPT over it, but when I'd go into PE, it would kick into REP mode. I babied the car to the dealer and had them flash the full Camaro program in, and then overwrote that with my HPT one (diff. injectors, etc. wouldn't let the tech even get the car started).

Since then, it's worked fine. From what little I understand, there's like 8 OS segments in these, and HPT only writes to some of them.
05-01-2015
jaydubb71

trbo355? Whats up sir! Thanks for the advice. Im over at TTF also...
05-11-2015
trbo355

Quote:

Originally Posted by granatl

Over a year ago, my wiring harness melted on a header and shorted out the E38 PCM. I bought a refurb from GM that had like a 2008 Saturn OS on it. I put my Camaro HPT over it, but when I'd go into PE, it would kick into REP mode. I babied the car to the dealer and had them flash the full Camaro program in, and then overwrote that with my HPT one (diff. injectors, etc. wouldn't let the tech even get the car started).

Since then, it's worked fine. From what little I understand, there's like 8 OS segments in these, and HPT only writes to some of them.

What year Camaro do you have?
05-11-2015
MikeOD

The 158 mph VSS problem is probably an automatic calibration without a TCM present.

As far as your TAC problems...You can't flash the TAC with HPTuners. The throttle calibration tables you have access to are not the TAC. If you don't keep them compatible with the TAC calibration in there, you'll run into problems. If you truly need a full rewrite on an E38, you have to pay the dealer.
05-13-2015
Bluecat

If you do a search, Brand "E" actually has a nice little document that tells what OS's are swap compatible on the E37, E38, a E67. Personally I think they are a little more flexible than they state as their take is a little more extreme than having a breaking point in the 08-09 years. They make it look as if even among the 06, 07, 08 stuff that you can't just swap at will. Regaudless, either by observing the 08-09 line and since having that document to go off of, I've been lucky enough to not ever brick a new style ecm.

As far as the internal TAC module is concerned, it sucks that we can't read and write that part. I don't care if we can edit it, but not being able to change it cripples what we can do with these ecm's. Oh for write entire to actually be just that, like the good ole days...

I have found from doing lots of ecotecs on rail buggies, that so long as you copy the etc settings from the original tune into what ever os you want to put on there, it usually works. If there is much difference between the numbers in the TAC and the tune you get dead pedal and p0606 stuff. So a common example for me, would if you have a retro swap car roll in with a 08 auto truck tune. Has speedo and idle problems that you cant fix without more access to more tables. Fix is to put a compatible 08 Vette M6 tune on it. But then you get a deal pedal because TAC module tune is different and we can't change it. If you go back to the original tune and copy the whole engine/airflow/electronic throttle tab to the new tune, it usually works to make the TAC module happy.

Now this is unwarrantied advise. From what I can tell a mismatch in tune/tac won't brick an ecm, as anytime I've done it its let me put it back the way I found it and been just fine. That may not be true in every situation, so I don't want people bitching about smoking a computer from my advice. Use at your own risk. If you follow proper procedure for what os you can swap with other os's, you should be pretty safe to make these kinds of changes.
05-13-2015
MikeOD

Quote:

Originally Posted by Bluecat

If you do a search, Brand "E" actually has a nice little document that tells what OS's are swap compatible on the E37, E38, a E67. Personally I think they are a little more flexible than they state as their take is a little more extreme than having a breaking point in the 08-09 years. They make it look as if even among the 06, 07, 08 stuff that you can't just swap at will. Regaudless, either by observing the 08-09 line and since having that document to go off of, I've been lucky enough to not ever brick a new style ecm.

As far as the internal TAC module is concerned, it sucks that we can't read and write that part. I don't care if we can edit it, but not being able to change it cripples what we can do with these ecm's. Oh for write entire to actually be just that, like the good ole days...

I have found from doing lots of ecotecs on rail buggies, that so long as you copy the etc settings from the original tune into what ever os you want to put on there, it usually works. If there is much difference between the numbers in the TAC and the tune you get dead pedal and p0606 stuff. So a common example for me, would if you have a retro swap car roll in with a 08 auto truck tune. Has speedo and idle problems that you cant fix without more access to more tables. Fix is to put a compatible 08 Vette M6 tune on it. But then you get a deal pedal because TAC module tune is different and we can't change it. If you go back to the original tune and copy the whole engine/airflow/electronic throttle tab to the new tune, it usually works to make the TAC module happy.

Now this is unwarrantied advise. From what I can tell a mismatch in tune/tac won't brick an ecm, as anytime I've done it its let me put it back the way I found it and been just fine. That may not be true in every situation, so I don't want people bitching about smoking a computer from my advice. Use at your own risk. If you follow proper procedure for what os you can swap with other os's, you should be pretty safe to make these kinds of changes.

I did exactly this recently with a friends 1971 Blazer with an 08 truck 6.0 LOL...08 Vette file with throttle settings from the truck copied back in...all is working great.
05-14-2015
UR50SLO

1 Attachment(s)

I have a 2008 G8 ECM that I'm helping a guy with... He had it to Lingenfelter to take the VATS out and ... I can't see that they actually did anything.

It will start for just a moment then die...

The VE tables are blank in it for some reason... I don't have the stock file and none of the other stock files I download have the same setup...

I have all the VATS disabled and DOD... Anyone have the info for the VE tables?

Take a peek at the file and see if I'm missing anything else.
Thank you!
Scott...
05-20-2015
brawls43

UR50SLO, I'll try to take a look at your G8 tune tonight, I've been working with an 09 G8 tune recently too.

More to the rest of the thread, I'm trying to look into changing some of the segments. Not only is the project swapping from an auto trans G8 to a manual trans, but I think I need to try to use a different pedal. I have the G8 pedal, but its all plastic, and the installation needs to change the shape of the pedal. So using an Envoy or Vette pedal would be a lot easier. Being a total newbie, I'm trying to figure out where to get these other segments to put in my file. Heck, is it even possible what I'm doing or am I up a creek without a paddle?
05-20-2015
schpenxel

Quote:

Originally Posted by UR50SLO

I have a 2008 G8 ECM that I'm helping a guy with... He had it to Lingenfelter to take the VATS out and ... I can't see that they actually did anything.

It will start for just a moment then die...

The VE tables are blank in it for some reason... I don't have the stock file and none of the other stock files I download have the same setup...

I have all the VATS disabled and DOD... Anyone have the info for the VE tables?

Take a peek at the file and see if I'm missing anything else.
Thank you!
Scott...

Engine-->airflow-->dynamic, set high RPM disable & high RPM re-enable to 50 and 25 so that it uses MAF only (no VE) when over 50 RPM's.

Otherwise it is still trying to use the VE table, which is blank, so I don't expect that will be making things work very well. Not 100% sure it's your problem, but it's worth a shot. That's assuming he is running a MAF.

What engine is it? You should at least be able to find something in a very rough ballpark to stick in the VE table to get you going. It's showing up as a 6 liter Pontiac G8. Is that what the engine came out of?
05-20-2015
LSxpwrdZ

Really stinks the "Write Entire" doesn't actually do what it says. I've ran into this situation on a couple occasions where I needed a manual file instead of auto and doing the write entire with the normal C6 OS didn't work for me. When logging the car sometimes it would pull up the old SUV as the vehicle type and other times it would pull up the C6 as the vehicle type. It was a mess to say the least.

If doing alot of retrofits using the E38/67 it would be a good idea to purchase a subscription to TIS and a cable to flash OEM programming into the ECM then modify the tune with HPT from there. OS swaps don't work the best with HPT as the only tool doing the swapping from my experience.
05-21-2015
brawls43

Quote:

Originally Posted by LSxpwrdZ

If doing alot of retrofits using the E38/67 it would be a good idea to purchase a subscription to TIS and a cable to flash OEM programming into the ECM then modify the tune with HPT from there. OS swaps don't work the best with HPT as the only tool doing the swapping from my experience.

Is this the TIS sub you're talking about?
http://www.acdelcotechconnect.com/sh...ogram/tis2web/