Gearbox fault, DSC fault, parking break fault,loss of power.

[Katee34]

I have just returned from France having down some 2000miles on roads of all types including lots of motorway – without problems (and hence with a well charged battery). However travelling  a few miles into London today , I experienced a loss of acceleration response from the throttle.  When going to accelerate the car would not respond unless the throttle  was released and reapplied.  Each time the revs would rise to circa 1500 and die away again.  In the end I had to pull over to the side. I put the car in neutral and tried to rev – same response. Then the problem seemed to clear and I continued my journey.  However by this time I had the following warnings

Gear box fault, DSC fault ( DSC light also on), park brake fault.  DSC would not switch back on by touching the button- but car drove normally.  By the time I had arrived some 15mins later the parking brake warning had disappeared.

Switching on again to return, only the gear box fault warning reappeared.  Car drove normally.  DSC could be turned on and off without problem. On arriving ,stopping and restarting engine all warnings had disappeared!

Taking the car out again for a test run there  were the odd occasions when there was excessive delay to throttle movement – well in excess of turbo lag, but no warnings . The original problems and warnings could not be retriggered but it removes confidence not being able to accelerate reliably when necessary.

I note that this problem has some similarities with other reports of the same combination of warnings but not the loss of acceleration control.  Any ideas?

[Bob G]

Hi Katee34,

I had the same problem with the addition of "vehicle too low". Several shops and Jaguar dealer couldn't pinpoint the problem because it was intermittent. I have been working on cars for 37 years and this problem made me want to pull my hair out because it had been going on for 4 years. Very recently I spent a month trouble shooting and testing. The good news is the fix is easy and free. There is a loose connection from the Engine Control Module (ECM) to a cluster of wires on the back of the engine assuming you have the 4.2L engine (see photo). Push down hard. Now it purrs like a kitten.

Depending upon weather conditions the car would loose the acceleration control when hot or when idling. Limped home many times, but never left me walking. The other adjustment made at that time was the connection to the main fuse box under the hood. I don't think this was the issue because it was clean and secure (see photo). Good luck.

Bob G