Date: 9/16/21
By: Mike McGinnis
Vehicles affected:
Software affected:
Firmware affected:
After an ECU reset, the AVCS system goes through a system of checks and adaptation prior to the ECU entering standard operating conditions. In addition, whether the ECU has been reset or not, a reduced set of checks needs to occur after each engine start.
The ECU is reset when new, after a reflash, when the ECU loses all power, or when it is specifically reset via the AP or a scan tool.
For the vast majority of vehicles, this poses no concern, but we wanted to provide an improvement for the following use cases:
The applicable ECUs were further reverse engineered to find tables related to the AVCS thresholds and how the tests work. We narrowed down which tables offer an easy method of improving the AVCS activation process on certain vehicles and have made them accessible in our tuning software.
Set your calibration to target AVCS positions of 5 degrees or more in the 0-2000 RPM range. That's likely already the case, but this will help satisfy one of the ECU test procedures.
With practice I'm sure you can beat these times, but my first time performing the tests it took me:
Ecu Immediately After Reset (Approximately 5 seconds)
ECU without recent reset (Approximately 2.4 Seconds)
The AVCS system can phase the cams while Post Start AVCS Disabled Map Ratio is 1, as long as the activation flag monitors we've added are at 1 and the vehicle is off idle. However, you'll be operating in alternate ignition tables which are generally not desirable and this is not suggested. This is why I'm suggesting having the vehicle operator simply use Post Start AVCS Disabled Map Ratio of 0 on the AP gauge, as the chief indicator that the AVCS system is ready to drive aggressively. |