RomRaider

L/U prohibition.
What mean about L/U -?

Good question. My guess would be "lockup" based on this part of the A2L :



What exactly is locking up : not sure. A/C clutch ?

The other option for "lock up" could be torque converter.

Yes of course, I forgot about that one. But I vaguely remember some parameters that had "L/U" in them that didn't seem AT-related at all.

Let me toss out another thought....
Could it be locking the cam phasers in the "home" position as the engine is turned off?

UPDATE: Nope!!
The locking/unlocking of the cam phaser is done by retarding or advancing the cam phaser via the duty cycle to the VTC solenoid.

I have found a few L/U maps related to the condition of AC. So lockup could refer to AC, torque converter, and whatever else is out there. But I think the primary one is going to be the AC due to the fact that torque converter operation is controlled by the TCM most likely.

So far with my current definitions, the torque converter related ones are "lockup" while the AC related ones are "L/U" Whether this will stay consistent or if I'm even right on where each belongs, who knows. But at least we have a good general idea!

Of course a simple enough test would be to watch the RAM location of one of those LU flag variables and play with the A/C button !

Possibilities of lock up;

Lock up Solenoid Valve
Torque Converter Lock-Up Clutch
Lock-Up Upshift Control Solenoid Valve
Lock-Up Upshift Valve Body
A/C Compressor Lock Up
Lock Up Valve Body
Lock Up Shift Valve

So by the looks of it, the lock up maps will be related to torque converter lock up and AC compressor lock up. This isn't guaranteed but that's all that's showing up in shopkeypro for "lock up" lol

From what I've seen, everything lock-up (L/U) based has been talking about torque converter lock-up. So I'd say most, if not all, of the L/U based parameters are referring to the torque converter.