Ls400 limp mode causes?

[1uzfehilux]

Hi, I’m wondering if anyone has a list of causes that will cause limp mode? 

The reason I ask is that I’ve done an engine swap and I’ve put a 1998 1uzfe Vvti into my hilux. I’ve converted the engine to manual and have two recurring fault codes.. vss, which I don’t have the facility for on the manual box, and fuel pump control because I’m running an in-line Bosch 044 pump.. sadly I can’t get obd2 talking to my Ecu so I can only check codes using the flashing cel. 

Any help would be greatly appreciated!

[ambermarine]

As I understand it Limp mode is a pre- determined  engine rpm for a low gear ratio when a fault occurs in the autobox to stop further damage by changing gears .

If you have converted the drive to manual the the engine ecu as been confused because its getting conflicting signals or no signal at all from a defunct auto gearbox.