Hello, excellent forum. Glad I found it
Recently my TJs main battery died after leaving the vehicle a bit too long without running the engine. I took the battery out and charged it but didn't put it back 'til about a week later. Now it's back in and the red lamp on the immobiliser is permanently ON, no flashing. Pushing the unlock button on the remote (I have the black key) causes one of the relays in the black box to click but the starter motor won't turn. All other electrics are on and working.
I've taken the black box out from inside the dash and by shorting the starter I can get the engine to fire up but it dies straight away.
The only error code I get is '12' which I guess is normal.
How exactly does my immobiliser work?
How can I bypass it to prove that it is faulty?
Do I need to send a signal to the ECU to keep the engine running?
Lots of Q's as this is all new to me since this morning.
TIA for your help people.