XJR gearbox issues

[timstokes1990306]

Hi there I have a 1998 xjr which has intermittent issues on the gear box
So sometimes you go to start up and put in drive and nothing happens just sits there like it’s not in gear same if you got to put it in reverse
But you have no throttle response at all unless you place it in neutral or park
No warning messages come up at all when it’s doing this

If you start the engine straight away and put it in gear then it will drive but I keep getting gearbox fault flag up and the codes I got were P0780 and P0730
Then it doesn’t change gear correctly but if you switch it off n on then it will work again

If you accelerate moderate it will behave and change gear smooth , other times you go to accelerate like off a round about and it seems very jerky

Then if you boot it it holds the gear but once you let off it then clunks and cannot make its mind up on the kick down and throws the fault again

I did do a replacement conductor plate along with filter and oil last year but hasn’t fixed this so o don’t know if it’s the TCM or the solenoids inside the transmission causing this thank you

[mike020150]

The diagnostic codes listed can both point towards a low gearbox oil level and/or a lack of internal gearbox oil pressure. Refilling the box after an oil change needs to be done with the engine running and whilst the gearbox is cycled between gears to ensure all the solenoids are filled adequately. Also, the correct markings on the dipstick have to be used. These are meant for 25 degs or 80 degrees gearbox oil temperatures, cold and hot respectively. If the correct filling procedure has been followed, it's likely to be an internal hydraulic failure of some kind and suggests that the gearbox requires an overhaul. Mike.