Toyota Repository

Quote:

Originally Posted by Wischman

Hello, I'm new here and had a couple questions about this process that I'm betting some of you very smart people could answer. I've read over much but still have some gaps in my understanding.

1) When writing .CUW / .HPT files to the ECU are we only writing to the ECU that controls the engine and transmission and not all of the other modules (HVAC, ABS, etc)?

Correct, we aren't writing to any BCM.

Quote:

2) I have a 2011 Sequoia 5.7 Flex Fuel and am wondering if I can use the Tundra files and tunes without a problem.

You'll always use the virtual read provided in VCM Editor. You can copy changes over from a Tundra file using the Compare tool.

Quote:

3) I'm looking to delete the Secondary Air Injection System (SAI or SAIS). The later model Tundras don't even have this system, if I used their tunes (is this the .CUW or the .HPT files?) that should completely eliminate the system, correct?

You can't eliminate the system by loading a different calibration (later Tundras still have SAIS, anyway).

Quote:

4) If I used a later model Tundra Tune that is not a Flex Fuel, would that eliminate all of the Flex Fuel sensors, etc and therefore essentially make my vehicle a non-Flex Fuel (this is something I am after, as the Flex system seems to degrade over time)?

There are no sensors, ethanol percentage is determined virtually; converting cannot be done via calibration alone.