Citroen XM Forum

Hello Jimmy here hi to all ihave a green two litre ato 1998 also a wine 2'1 diesel manual !I had to change the battery and the immobilizer locked out on red this is the 98 petrol it will not start would appreciate any help thanks

Do you mean the keypad has locked out flashing red, or the alarm has locked on?

If it is the alarm try disconnecting the battery, turn ignition key to Ign, connect the battery.

If it is the keypad flashing red, the power has been lost.
Power is supplied from the double injection relay.

Link to latest circuit diagrams from Gabor.
download/file.php?id=9586

There is no diagram for 2.0 16v, but is for the auto-gearbox and starter circuit, but the keypad operation I the same for all models.

I believe these are the correct diagrams for your car and Ecu.

http://oldipcxm.free.fr/schematek/513-04.pdf

The diagram descriptions are here. http://pepon1.free.fr/CITROEN%20XM_fich ... mas.htm#51

Thank you, sorry I'm just getting used to these forums.
The keypad is on static / constant red no matter what I do.

Also is the ignition key talking to the Engine control unit?
Thank you

No. There is no communication from the key. It litterally only unlocks the car and turns the ignition to power the car up.

Thanks for that also when I open a door the headlights flash on and off for a few minutes and a small red light is flashing on one of the switch's on the dash all the time. The red light on the immobiser is on all. Time not flashing.

The headlamps and internal indicator mean the alarm has been triggered. It sounds loke th siren is duff, hence no audible signal.

The keypad showing red means it is waiting for the correct code to be keyed in.
What happens when you press buttons and what when you enter the correct code. Possibly a button has a poor contact so the correct code isn't being seen. Is there a chance liquid has been spilt onto the keypad?

Watch carefully, the red light should blink on each button press.

Try doing an alarm reset.
- disconnect batt+ cable
- all doors closed, IGN off, keys out
- re-connect battery cable, and immediately Lock, then Unlock the car with the Remote (plip). Lock may require two presses of the remote lock button on the fob, to achieve full locking.
- then unlock, and alarm should be reset.

Procedure applies to OE alarm system, 1996-on.

White Exec wrote: ↑

Wed Feb 23, 2022 7:35 pm

Try doing an alarm reset.
- disconnect batt+ cable
- all doors closed, IGN off, keys out
- re-connect battery cable, and immediately Lock, then Unlock the car with the Remote (plip). Lock may require two presses of the remote lock button on the fob, to achieve full locking.
- then unlock, and alarm should be reset.

Procedure applies to OE alarm system, 1996-on.

If the plipper doesn't work... Leave the ignition on second position take the negative terminal off the battery and reconnect it. It will then also reset the alarm. If you listen you should hear a rapid flashing ticking of the indicators and alarm ecu box.

Thanks for your help. Tried them no joy.before ignition is turned on red is flashing when switched on red is static.when I press keypad buttons the red light.does not change.also the remote key does not lock the car .but central locking does work manually with key. Also I cannot get the alarm off i.have the owners handbook it doesn't even mention the alarm were they aftermarket fitting their is a good bit about immobilizer factory coad 0001 .to disable it. 0000 but first it must be started to change the coad I. Really appreciate the help it's quite tricky Jimmy b