Shift points, drive modes and lockup

Applies to: IOcan only. A gateway keeps the factory transmission control unit, which is what makes shift points untouchable. A standalone controller schedules its own shifts, so none of this applies to it. What this means

Two questions come up constantly:

Where do I change the shift points? How do I control torque converter lockup?

Not in this device. Both live in the transmission's own tune — the calibration inside the transmission control unit. The device has no parameter for either, and adding one would not help, because the TCU is the thing making those decisions.

This page explains what that means in practice, because "you can't" on its own is not useful.

What decides what

Decision Made by Changed by
When to shift The transmission tune Re-tuning the transmission
Drive mode behaviour (D, S, manual) The transmission tune Re-tuning the transmission
Torque converter lockup The transmission tune Re-tuning the transmission
Line and clutch pressure The TCU, from the torque signal Giving it a correct torque signal
Which gear is requested Your shifter, through the device Device configuration
The engine picture the TCU sees The device Device configuration

The device's job is the bottom two rows. It recreates the vehicle environment the TCU expects and passes your gear requests in. It does not second-guess the TCU's calibration.

What you can influence

Quite a lot, indirectly — and this is where to spend effort before concluding the shift points are wrong.

Give it an accurate torque signal. Shift scheduling and pressure both key off engine torque. A torque estimate reading high makes the transmission behave as though the car is under more load than it is; reading low does the reverse. This is the single biggest lever you have — ten-minute check.

Give it accurate road speed. The shift schedule is built on speed. A wrong diff ratio or wheel diameter shifts every shift point by the same proportion, and a few percent of error raises no warning at all. See Vehicle & wheel speed.

Give it accurate pedal and throttle position. Both are mandatory inputs. If throttle never reaches full scale, the TCU never sees wide-open throttle, and full-load shift behaviour simply never engages — which reads exactly like "it won't upshift properly".

Use manual mode. Paddle and sequential control let the driver override the schedule directly, which is often what someone actually wants when they ask about shift points. See the shifter pages.

Before concluding the transmission shifts at the wrong points, verify the three signals above. A car that upshifts too early or refuses to hold a gear is far more often being fed a wrong speed or torque picture than it is badly calibrated.

If you genuinely need the shift points changed

That is a transmission tuning exercise, on the transmission's own software — separate from configuring this device.

The device can flash OEM 8HP transmission control units and read TCU memory, so it is a capable tool for that work, but the calibration itself is its own discipline and is not covered by this configuration documentation.

Lockup specifically

The same answer, with one addition worth stating: getting lockup wrong has thermal consequences. A converter clutch that slips when it should be locked generates heat in the fluid. Because the strategy is in the transmission tune, the failure mode to watch for from the device side is not a lockup parameter — it is transmission temperature.

The Torque converter slip and Transmission temperature outputs are both mandatory on the OEM gateways, so route them somewhere you can see them.