2001 land rover diesel auto- it is refuses to engage top

Hello I'd 1st take a look at the colour of the transmission oil it should be a dark red colour if its black then it needs changing together with its oil filter. Also check its level with the gearbox warm and just after you've moved the selector through all the positions leaving it for a few seconds in each one and then back to park. You can top up the box through the side fill plug if required and make sure you use the correct oil for your car as the fluids are not all the same. Some manufacturers recommended a change of the type of fluid - Speak to the local dealer and parts dept - they will advise you on the updated fluid to use.. If that’s all OK then check all the electrical connections of the gearbox, remove each connector in turn and spray with contact cleaner. Check that the wiring to the gearbox is in good condition with no chafing or frayed wire If this is OK then check the selector lever linkage / cable under the car for any broken parts and or missing bolts as if this is coming adrift then it can rub on the car body or just bind up if this is all Ok it could be an issue with the MAF sensor as this is the primary load sensor for the engine and has a strong effect on the gearchangesMight also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage.you can do a quick fault find if you unplug the meter and run the engine without it.if the engine condition is the same then chances are the meter or the connection to it is faulty This leads them to be quite intermittent in the case of mild leaks its also worth cleaning the airflow meter by removing it from the car and spraying the exposed sensor wires inside the tube with a brake or switch cleaner - ensure that the cleaner is one of the old fashioned, non Eco type that does not leave a residue On no account touch thesensor wires with anything physical as they are extremely fragile