Mostly true the ECU has a set of parameters that can't be changed by doing a reset or disconnecting the battery. If doing a TPS replace the ECU reads what ever the closed throttle plate voltage as the 0% point and if you move the TPS you must disconnect the battery so the ECU will read the new TPS position at 0% throttle plate position this is about the only learning the ECU has. Now if you go and have a reflash done of the ECU all kinds of parameters can be changed, but still once the ECU is reflashed by an aftermarket shop it will only do what it has been reflashed to do you can't add of change anything other than a TPS % of throttle plate reading.