[suchy33]

Hello recently my g30 520xd 190ps started to have some weird problem. While accelerating with full throttle it goes good until 140kph, then it gets this fault code 4210A2. All it says is Power train gain: Fault in calculation detected.
after 140kph it gets reduced power and is very slow in acceleration. when in reduced power and full on throttle sometimes you can feel a jerky gear change or unpredictable downshift almost till rev limiter. Bmw service just want to replace a new transmission for a lot of money wiht addition that they dont guarantee that problem will be solved...
Other workshops just told me to keep on driving and getting the fault code so they can have more info to compare and that they can try swapping gearbox driver, but still they have no idea yet what to look for.. can someone help pls?

[Mikej0h]

Was the code read by a generic OBD2 reader, or ISTA? As I can imagine there might be hidden codes, or a more thorough explaination via ISTA...

[suchy33]

i think it was ISTA because it was done by unauthorised workshops aswell as bmw authorised service and they sent this problem to helpdesk still no answer to this fault

[suchy33]

is it worth to try and swap gearbox driver?