A tuning job that i did recently was a S4 Nissan Patrol that had been converted with a 6LT & 6L80e, the customer had sourced his doner parts from a VF, so I kept the original factory ECU (12656930) & TCM (24267577) operating systems, but we discovered some strange shifting patterns occurring.

What i found happening is the shift speeds were not following what was set in the transmission calibration, it would instead hold out shifts well past the pedal position set point for the speed.

For example, holding the pedal at say 40% the shifts for each gear should execute 1-2 @19kph, 2-3 @ 36kph, 3-4 @ 55kph and so on, however gear shifts were holding out as if the pedal was being pushed harder, resulting in higher rpm’s before shifting.

As i had been experimenting with this same os combination in a couple of other cars and not seeing this issue occurring, i figured it was likely related to a missing brake signal. So advised customer where to wire it into the ecu & place on the light side of the pedal circuit. This way the ecu can see a gnd when not applied, then 12v when brake applied.

Upon his return, I changed the ecu tune via some custom mapped parameters to disable the analog brake select input & then confirmed that ecu/tcm both see the brake being applied, took it for a test drive & now the shifts followed at the expected pedal position.

So if your wondering what this analog brake select is about, well prior to the release of the VE commodore most brake inputs were a simple on/off switch like below.

With the VE\VF it’s a position sensor, so works like most 0-5v sensors, they did a similar setup with the clutch pedal on the 06-08 manuals where it was changed from a switch to a position sensor. I also have the clutch type sensor mapped out & have utilized it on on ecu upgrades on manual cars, where the only previous option was to disable the clutch interlock for starting.