Where is manual backup gas cover release on a 2005 s type jaguar

It is a regulatory safety device. You need to fix the Emergency Brake, not find a way around defeating it.

Check out the videos

https://www.google.com/search?q=2005+jaguar+s+type+emergency+handbrake+release

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not familiar with jaguar but most cars it is accessible under the back seat

what is it doing when you try to start it. have you tried some gas line anti freeze it is only for gas lines

Call the Jaguar Dealership about your problem. Jaguar issued a TSB about electric brakes applying and not releasing.

You should be covered for free. . Another problem was transmission engaging reverse when accelerating away from a stop.

This is a safety concern and can cause an accident and injuries in both cases. Your dealer can resolve these problems with anupdated programming to the cars ECU .

Its easy but access is a little difficult. I moved the hose a little out of the way to get a few extra mm by opening the battery cover and fuse box. Then on the light, just flip the 2 clips on either side of the black plastic cover to open. You will then see a centre electrical connector and a separate smaller one. The centre one goes on the bulb - just pull it off. Then there is a spring clip holding the bulb in - release both sides and take out the bulb. Put in a new bulb making sure never to touch the glass part. Reverse all the above and the job should be done.

there is a release lever in the trunk beneath the gas cover you can push to release

There is no release inside the car  if you go to the dealer  with proof its youer car they will order a key thats the easy way D

my Jaguar X Type gas cap "sticks". I can open it by wedging a corner of a credit card in the left side or the cover, then go in the car and pull the lever. There are two flimsy metal bands that hold the cover in place and they sometimes bend and then the release doesn't work.  it should open easily with the credit card wedged in; then bend back the metal bands into shape.