C5 X7 VTR Tourer 2L Immobiliser Fault

[completediv]

Hi

After returning to car after a drive to town, key fob wouldn't open car. Opening by key set off alarm and immobilised it. Half an hour later key fob worked and I drove home not faults showing, parked up and locked car with fob. Tried to open car with fob - nothing. Opened with key, alarm trips and immobilses car. At different times I get Electronic Security Fault displayed, Service light displayed or nothing. Plugged in cheap OBD reader, no fault displayed or recorded previously. Mysteriously restarted and I managed to open window to try BSI reset.

Following Marc's BSI reset procedure all done as instructed but could not get fob to operate central locking (last step), but after opening with key managed to start car, close window, switch off and open and close car 15 times using fob. Locked it, returned 30 mins later fob wont open car!

Sorry for the long intro but does anybody have any ideas on how I might be able to fix this issue?

Thanks in advance

[Kees]

Ik think you have to replace the battery in the fob, as you describe the problem, it seems bad/dirty contacts in the fob.

[completediv]

Hi Kees

Thanks for your response. I should have said that I did change the battery for a new one and all contacts seemed good. I also tried my spare fob - nothing doing.

Cheers

[Kees]

Is your spare fob initialized on the system with the diagbox?

[PaulC5]

Not sure if this will help but I replaced the fob battery in our Cactus when it stopped unlocking. I used an Energiser one but it stopped working again a bit later. I then replaced it with a Duracell one and now ok. The negative contact surface on the Energiser one is lots of small segments whereas the Duracell and original Panasonic are much larger so at a guess that may be something to do with it. The spare one was working ok.

On our previous C5 if the spare was not used approx every month it would not work unless initialised or in conjunction with the other fob used alternatively a few times to lock/unlock the doors.

[completediv]

Is your spare fob initialized on the system with the diagbox?

Hi
I don't have Diagbox so I think the answer is no

[completediv]

Not sure if this will help but I replaced the fob battery in our Cactus when it stopped unlocking. I used an Energiser one but it stopped working again a bit later. I then replaced it with a Duracell one and now ok. The negative contact surface on the Energiser one is lots of small segments whereas the Duracell and original Panasonic are much larger so at a guess that may be something to do with it. The spare one was working ok.

On our previous C5 if the spare was not used approx every month it would not work unless initialised or in conjunction with the other fob used alternatively a few times to lock/unlock the doors.

Hi Paul
I'll check and come back to you on this. The new battery I put in yesterday is Energiser, so I'll go check/swap it out

My spare hasn't been used for at least a year, maybe more, so when the rain stops I'll try and reset it and let you know how I get on

Thanks for the input.

[Richard_C]

I have a vague memory of a similar issue a couple of times but can't recall if it was the X7 or the SAAB I had before or both.

There was something about unlocking and opening the door, letting the alarm sound then very promptly - within 10 seconds?? of opening - putting the key in the ignition and starting the engine. That teaches the car that the key that opened it has the correct immobilizer chip in it.

Costs you nothing apart from a few seconds of eardrum-assault so worth a try.

[completediv]

I have a vague memory of a similar issue a couple of times but can't recall if it was the X7 or the SAAB I had before or both.

There was something about unlocking and opening the door, letting the alarm sound then very promptly - within 10 seconds?? of opening - putting the key in the ignition and starting the engine. That teaches the car that the key that opened it has the correct immobilizer chip in it.

Costs you nothing apart from a few seconds of eardrum-assault so worth a try.

Hi Richard
I'll try it and let you know how it goes. Be tomorrow as it's wild and wet in West Wales today!

Thanks for your input

[Richard_C]

I'll try it and let you know how it goes. Be tomorrow as it's wild and wet in West Wales today!

Pity its Tuesday not Wednesday, otherwise you could say it's Wild Wet Weather in West Wales Wednesday and leap to the top of the Forum alliteration league table in one go. Good luck.

[wheeler]

Opened with key, alarm trips and immobilses car.

I know the alarm goes off but did you actually try to start the car at the time? if the alarm is going off switching the ignition on with a programmed key should turn the alarm off, The car should also still start with a dead key fob battery.

[completediv]

Opened with key, alarm trips and immobilses car.

I know the alarm goes off but did you actually try to start the car at the time? if the alarm is going off switching the ignition on with a programmed key should turn the alarm off, The car should also still start with a dead key fob battery.

Tried to start it and would try a brief crank then nothing alongside either Electronic Security Fault or Service Light indication. These codes do not appear on OBD reader as either current or past faults.
As I've encountered in the past same issue will display different faults or occasionally clear themselves randomly to return randomly

[PaulC5]

If you put the key in the ignition switch and open the driver's door do you get a warning - if so the immobiliser is recognising the key. If it is not recognised I thought the engine would still turn over but just not start.

Have you checked the 12 volt battery voltage, fully charged should be about 12.7 volts but if much below about 12.3 volts it needs charging.

[completediv]

Hi all,

Issue continues, presenting in a multitude of different intermittent, faults. Key fobs work, then they don't. Key always open and shuts doors. BSI reset doesn't fix issue. Sometimes alarm goes off, sometimes it hasn't set so doesn't go off. After entering and starting car successfully, return to fob not working and inability to start car. Multiple faults appear in display, the most constant being Electronic Anti Theft Fault or Service but odd ones like ESP. They can sometimes disappear for no apparent reason. Can't see them on OBD reader. When in fault car will attempt a crank but shuts down.

I suspect water ingress and on checking found bad seal and tears on Scuttle panel (Cowl Air Intake Grill). So I'm going to remove it to investigate - when the weather allows.

When removed will this give access to wiring in the bulkhead?
When removing are there any parts easily damaged?
Does anybody know if this part is the same for all C5 X7 model years? I've seen part no 8251CY advertised for 2012-17 cars. My car is 2010 Tourer 160 2L. Does anybody know the correct part number? I'm asking this as I understand the Forum parts query service is still down.

Any advice/suggestions gratefully accepted. I've had this car for 15 years and love it, but this could be the last straw!

.

[mickthemaverick]

New to this issue, but my first reaction on reading the first post was a potential battery issue. When the battery voltage wavers between good and bad it tends to throw up all sorts of weird and wonderful faults and warnings so I would, as Richard suggested, make sure the car battery is good, showing 12.7+V when resting and over 14V with the alternator charging. If the battery is poor then an element of luck comes into what works and what doesn't so check that fully and all the connectors and wiring around the BMS and engine fuse box.