Hi guys, I have a recently rebuilt 4 speed btr gearbox.

The sports mode is not engaging when you move it over. But more annoyingly it is causing PARK and DRIVE to show 3rd gear when it’s not. Then it gets stuck in 1st.
Have to turn car off and put in park to reset issue. Drives fine for a while then randomly the D for drive will switch into manual mode when I haven’t touched the selector.

Something electronic is causing it to malfunction and get stuck and I can’t figure it out.

I have checked the shifter cable and bushings, all seem fine and working.
Disconnected battery for 10 mins to reset computer, no difference.

My mechanic put his analyser on and found a few codes (P2129, P2138, P1240) all relating to Throttle/Pedal Position Sensor/Switch Circut/Voltage. I have had a replacement throttle body but do not think this would affect the sports mode in the gearbox.

Anyone who’s had a similar issue please lemme know what fixed your issue!

Did you manage to fix the issue buddy?

did you remove the console & look at the circuit board to the left of the selector?. there is a small magnet attached to the selector that sits over what looks like a transistor [not actual transistors but i've forgotten it's name and there are three of em] and when it [magnet] passes over em you get the gear changes. if the magnet is missing you will have no sports shifting.


cheers