View Single Post
tymwalk tymwalk is offline
Junior Member
Posts: 80
Join Date: Sep 2021
Car: 2021 Mazda CX-5 Turbo Carbon Edition
Default 01-07-2022, 02:05 PM

Originally Posted by jcrout7992
Please explain that entire sentence in layman’s terms.
I originally missed the part about you only experiencing issues in 1st and 2nd gear. I saw that in third gear you had as much power as the ECU is going to allow so I didn't see an issue. In the JB4 logs, the LOAD column is your MAF sensors output. Multiply it by 10 for it to be scaled correctly. The JB4 for whatever reason gives the value at 0.1x what it should be. None of this is really important.

Modern turbocharged cars take the pedal position and other factors to determine a target torque value for the engine. That target torque is then equated to a boost target. Each gear has a target torque value versus RPM. Terry says that it may need an IAT spoof so that the ECU doesn't lower the target torque when a threshold LOW IAT value is met. Your throttle position in 1st and 2nd gear is controlling the boost target and the car expects to see a specific value of MAF (g/s) versus throttle position.

I am suggesting that when the V1 Mazda JB4 is equipped with a MAF sensor that the MAF values could be intercepted to tell the ECU to open the throttle to achieve the desire torque values even if they are LOW IAT limited.

This is all guessing at how the ECU logic operates until someone cracks the 2.5T ECU for all tables.

Pedal down -> Torque Table (TEMP TOO COLD) -> Lower Boost Target


Pedal down -> Torque Table -> Boost Target -> MAF Limiter -> Throttle cut
Reply With Quote