Mercedes 7 speed gearbox stuck in drive

[Trustmeimadoctor]

Hi got the 7 speed gearbox in w203 320cdi. Its now not started shifting from drive but if turn the car off i can get it out and then it works for a bit.

I read that the brake light switch can cause issues but i havent seen it in relation to moving from drive only from park.

Anyone any ideas?

[stevieturbo]

The obvious thing would be to check for fault codes.

[vat19rotax]

think the brake light switch was in respect to the 5speed 722.6 Gearbox, the 7speed 722.9 in your car I think it may be an ISM Control unit, but do check fault codes, there is normally Current & stored faults get them cleared after reading initially, take a video of them for checking purposes

[Trustmeimadoctor]

no fault codes logged. Brake switch seems baked into the pedal unit its self. If brake is pressed you cant shift out but if foot is off brake you can shift fine