Originally Posted by
APS
For all those who don't know, spoofing the FICM does work within reason. However there are potentially severe side effects. Be careful, make changes in moderation and always datalog what's going on. That includes connecting to the ICP on the analog cable inputs so you can see what it's actually doing.
It really screws up torque calculations and skews transmission adaptives. I have seen them go for roughly 10,000 miles and all of a sudden the trans adapts stick at minimum adaptive. That's right, I didn't stutter, MINIMUM and the trans will do nothing but slip at anything more than 15% throttle. No joke this happened with a SCT can calibration.
I'm not saying don't do it but if you do it for a customer you better damn well know what you are doing.