You need to start the car and then disconnect the immobilizer while its running, if its the same as mine the buttons for the immobilizer will be beneath the ashtray?
The plastic thing that the buttons are on lifts up and you can disconnect it from underneath by removing the plug.
If your having problems with the code for the immobilizer try disconnecting the battery then re connecting it and it should reset the immobilizer code to either 0000 or 1111, start the car then disconnect the immobilizer as above.
there are 4 on the front of your engine, if it is the turbo model the 1 behind the pump is a pain to do, you will need a 12mm deep socket and a 8mm spaner
AnswerUsually located at the top area of brake pedal under dash I did my 2000 306 HDi today. Remove the plastic fuse box cover. Remove the convoluted air pipe. Remove the 4 nuts that hold the steering column and lower it as far as it will go. Sit in the seat (ie you dont have to be laying in the footwell upside down) put your hand in above the column and up through the hole, the switch is to the right, (RH drive car) pull the wire and the switch will come out of the hole in the bracket. Afrter plugging a new switch into the loom, push the switch throught the hole, turn on the ignition, keep pushing the switch in (it clicks every time it goes in further) until the brake lights go off. Press one more click. Bolt in column, replace air pipe and fuse box cover. Hard the first time, 20 minutes after you have done it!Hi. Did my 306 1.9 TD XR 1998 yesterday. Unbolting and lowering the steering column did the job. Very easy, however be carefull when refitting the steering column as it allows some adjustmest from side to side. Watch for the marks made by nuts.Read more: How_do_you_change_a_peugeot_306_brake_light_switch