E67 PCM Issues

[96LT4C4]

There?s a hptuners segment stating very specific about overwriting OS systems and writing different operating systems in different ecu?s especially writing e38 and e67 your going to spend more time chasing your tail unless you get the dealer to rewrite the ecu to its original state. The other issue is fuel pressure settings on e67. It could have variable pump turned on. My 2013 zl1 has e67 ecu so you might have the variable pump software in it. If you don?t find out your actual fuel pressure and if it?s not turned off your in for a whole lot of headaches. I doubt they wired in fpcm to 55 Chevy. Last is the maf re-enable under airflow/dynamic set real low cause this will really give you low throttle headaches cause a cammed car doesn?t have steady low rpm vacuum either. There?s a good reason gm set the maf rpm boundaries high. Low rpm is not anywhere near as accurate as a tuned VVE w map sensor. Basically speed density mode. Best of luck. I don?t like to tune cammed car as everyone is different and has it?s own headaches.

I really like the old LS1 411 PCM....LOL Back in the day when "write entire" meant write entire. Not, oh by the way, we left some of the segments out. You can't edit those and you have to find out the hard way.

The 55 does not have the FPCM. Right now we are currently looking for a factory TBSS computer LS2. The 6cyl computers are a dime a dozen.

[Jon S.]

The E38 and E67 ECM may be thought of as “dual core” processors. The main calibration (6 segments) is contained in one of the cores - which is “read and write” accessible. Throttle controls (or throttle watchdog) is contained in the other core - which is “write only” accessible. Tuning software cannot read this core, and therefore cannot make changes to the specific calibration therein. There is an option in HPT to blindly write a generic Slave segment, but that still leaves one segment untouched. For liability reasons, this a feature that we will never use.

GM designed the computers this way for safety reasons, and they work very well. It just means that a replacement computer must be initially programmed with GM software, to fully program the “write only” core.

[jpierro79]

gm separates different segments like Jon S said. the other way to look at is like it has a solid state drive for certain sensors and the ecu pulls readings from multiple sections to spit out a calculation. Imagine you have a solid state hard drive for your injectors then one for your pedal and tb then another for your ignition control and the ecu pulls from all of these at once in order to create calculations to run except you can't change the information on one of these hard drives so the information is no longer accurate. Im not 100 percent if its like this but i would think we cant access it cause its like trying to rewrite a bios on a motherboard. That always requires special equipment. It requires a j2534 module and a digital charger and paying for software. the j2534 and sofware just to connect to a car is 3k. Then each manufacturer makes you pay hundreds to have access to the software. It becomes stupid expensive and thats why its soo much money and you should NEVER write the wrong operating system in an ECU.