I must admit, what you’ve described doesn’t sound like any of the ‘usual’ 5HP24 issues.

Your statement that the problem appears worse when cold immediately flags low fluid level as a possible cause. Have you noticed any leaks at all? May be worth checking the level - this is the procedure:



In case it needs it, only use Mobil ATF LT71141 for topping up (ZF Lifeguard Fluid 5 and Pentosin ATF 1 are difficult/expensive to source here in the UK).



Because there are so many potential faults (mechanical, hydraulic, electrical, electronic) we’re heavily reliant on the diagnostics to give us a clue as to what’s going on inside the transmission and transmission-specific DTCs are usually in the format ‘P0735’. What piece of kit are you using to read the codes? Is it just a generic code reader?

Phil