VAG (now VCDS) the car. Any limp mode will inflict this limiter on you.

Make sure the VSS itself is good. It's read by pins 1 and 65 on the ECU. Ignition on, neutral selected, raise the left front wheel and turn (lift both wheels if diff-locked together). It should fluctuate between 0 and 4 volts.

Check the continuity of the jumper as well, just in case...

Where did the chip come from?

DZ