Temporary Loss of Throttle Control

[Katee34]

I have got used to the slight acceleration delay on a turbo diesel /automatic compared with manual petrol, however I have recently and on random occassions experienced a level of hesitation on acceleration that is worrying.
Normally the response to increased throttle on a 3L D XF is impressive at any speed, however on occasion I now have the situation whereby pressing the accelerator produces --- nothing. The car seems to hesitate and even lose engine revs. The immediate reaction of releasing the throttle and reapplying the foot usually results in a bit of hesitation and then acceleration ( no warnings). However - at worst- repeated application of the throttle results in only slight blips in revs each time followed by a drop, with the result that the car progressively slows. This has happened on only two occasions so far both at relatively low speed in a built up area and with three amber warnings appearing – Park brake fault, DSC not available, Gearbox fault, accompanied by a light on the DSC button and amber park brake symbol. 
Strangely once the warnings have appeared the car drives normally. On switch off and restart only the Gearbox fault warning recurs. After 2^nd switch off and restart all warnings have cleared. In between such worst case events the car has done long and short mileage trips behaving normally.
Any ideas for the cause?
Before anyone mentions the battery it should be noted that both before and after such events the battery spins/starts the engine without any struggle.

[Mike_eng]

Hi Keith,

Have you checked the fault history?

One (of many) potential faults is the throttle position sensor as the track can wear.

I would suggest a full diagnostic at an indie Jaguar specialist.

Regards,

 

Mike