Red Light On Key Pad. 1-8 Petrol 16v R Reg.

[Guest 222jimbo]

Hi Folks,

I am a past XM owner, trying to help a friend, without IT access. The Situation as now.

My friend owns an "R Reg" Xantia petrol 16valve,everything working okay until it dropped a cambelt.Vehicle off road for sometime with battery removed. Replacement engine found for vehicle, but as engine is newer,wiring harness is different. Old harness removed & fitted to replacement engine. Engine fitted. First off Code pad would not accept last known code which worked until engine failed. 2 red lights. 0000c entered & new code, now getting 1 Green & 1 Red. New batteries in 2 button key plip(fob)& tried/checked re-synchronize key. Still showing 1 Red light. On turning key the fuel pump can be heard, the engine will crank, but will not start. Does the Red light (immobiliser)knock out the ignition at the ECU ? Has the ECU developed a memory loss, because it has not been used for sometime ? If ignition is left switched on for sometime will it reboot the ECU ? Now checking for poor electrical contacts/earths ! Plug will be removed to check for fuel & spark. Suspect RED LIGHT is the problem, but what has changed ?

ANYONE GOT ANY THOUGHTS THAT MAY HELP PLEASE. JIM.

[skysurfer]

I don't think my reply is going to help you much but as nobody else has piped up...

 

I've changed a diesel injector pump on a '97 P reg Xantia TD and I know that the keypad code moves with the injector pump. (You need to know the keypad code for the new pump you are fitting). The electronics on the pump is secured with a metal cover and shear bolts. i.e. fairly secure against tampering/theft.

In contrast, you're suggesting that the code resides in the engine ECU on a petrol Xantia? An item that can be swapped in seconds for an ECU that you (they) know the keypad code for. Doesn't sound anything like as secure.

I've just bought an HDi Xantia and apparently on that the imobiliser (inductive pickup from a chip in the key when ignition is turned on) is dealt with by the "body computer" which is at least fairly difficult to get at as it's in the dash above the heater fan. I assume this computer then communicates an imobiliser go/nogo status to the engine ECU in a reasonably secure manner.

The only slightly relivant help I can offer is that the IR keyfob is only for operating the central locking and deadlocks and alarm and it has nothing to do with the engine imobiliser.

 

Good luck!

Alan