C5 Wont Start

[geordie c]

my 2.2hdi wont start when i turn on the ignition i cant hear the pump running so i tried directly to the battery and it worked so tried it again off the ignition no joy ran a test from the plug on the filter to the plug on the pump the negative was ok but the positive there was nothing can anyone help me .this happen about a fortnight ago but changed the filter and charged the battery and it started happened again last week while shopping but finally it started got it home and now it will not start

[stephenhoughton]

my wife's c5 sometimes does the same thing. Runs fine then just will not start. Tried with jump leads but still would not start.

 I disconnected the positive clamp on the battery and when i reconnected it the car started immediately.

This has happened a few times since and everytime i just disconnect the positive clamp on the battery for a few seconds. Reconnect and away you go. I don't know what causes the problem but this ids the answer for my wifes c5 2.2

[qman3428]

This can cause permanent damage. The correct way of rebooting the car is to open the drivers window, close the doors with all accessories turned off and have the bonnet open,disconnect the positive connection for at least 3 minutes. Reach through the window and turn on the side lights and leave it for at least 15 seconds. Insert the key through the window and turn the ignition on (dont start the car) hold down the lock button for 10 seconds. Remove the key and check the doors lock and unlock. Turn off the sidelights, shut the bonnet and close the window, start the car and reset the clock. You have just rebooted the cars computer.

Saying a short prayer and doing a little dance is optional!

[andywat62]

Reading the rebooting of the cars computer with interest as may need to use it sometime!

I'm a bit lost though on holding down the lock button?

Are you able to elaborate  :unsure:

Andy