1997 x300 won't start

[jeffersonice]

My x300 has been garaged off the road since the end of November last year (2016). In April the battery was flat and I disconnected the positive terminal and recharged it successfully. I did not put the car back on the road as intended in April and so left the car until yesterday only to find the battery flat again so I recharged it.
Unfortunately the car would not start or turnover. I also noticed that the 'check engine' light went out at position 2 before trying to crank the engine.
I also have no central locking even by the key or fob. I am assuming that possibly the cmos battery in the security module could be dead as well.
I am only thinking these possible facts from reading other posts on here.
What else could cause the 'check engine' light to go out and the engine be dead? I haven't yet located the security module on the LHS of the
engine compartment.
When I wiggle the auto gearchange in park I hear the click and also when I put my foot on the brake pedal.
I would welcome any help/ advice /comments please.

[davidr]

Have you checked for the basics such as fuel pressure, spark etc?
I had the same thing with my 2001 XKR which hadn't been started for a while. When I tried the schreader valve on the fuel rail I found no pressure. I checked the connections to the fuel pumps and found them to have 12v so concluded that the fuel pumps (there are 2 on the supercharged models) were shot. After taking the tank out (easy once you've managed to disconnect the fuel pipes which isn't easy at all!) then I could see the pumps and both were completely pickled by the ethanol in modern petrol. 2 new pumps and all was well again!

[jeffersonice]

Thanks for your interest and reply David. Unfortunately it is not at this stage a question of ignition or firing as the engine is not even turning over and is absolutely dead. Nothing happens when you turn the key beyond position 2 and the fault as I see it is linked with with the ' check engine ' light going out so as not to enable cranking and the engine turning over let alone firing. Did your engine not turn over at all either, David?
I am concerned that the memory has been lost in the chip in the security module due to the battery being dead for too long maybe.
I am not sure if the security module has got a cmos battery in it to hold the memory for a while or not as I have seen differing opinions.
Thank you David as I do welcome any other lines of thought outside the box.

[davidr]

Sorry - didn't read your first post properly!
My immediate thought would be the gear selector interlock switch but you've tried waggling that. Have you tried starting it in neutral?

[jeffersonice]

It is a good one to mention David as I did find out about that quite a few years ago as I have had the x300 for 15 years and it has often not cranked unless I pushed the gear lever to the right to engage the interlock switch.
I still keep thinking about it being involved but I have tried moving it around a few times now without avail.
I have also tried starting in neutral and the click is there when I put my foot on the brake pedal with ignition on.
Do you know if there is a cmos battery in the security module David?

[robv12]

Check engine light should stay ON, this is the tell tale to sat the ECU is alive , and gives you "permission" to crank

Check engine light OUT means ECU is not switched on, so you will get no crank

read of these two posts, they may give some help

viewtopic.php?f=132&t=11236

and

viewtopic.php?f=131&t=11509



see how you go, and report back

[jeffersonice]

Thanks Rob, will do

[jeffersonice]

I have read the posts that you referred to me with interest Rob.
My main concern is whether the ECU on my car being dead is linked to the fact that the central locking has also been made inoperative at the same time even when using the normal keys.
If that is caused by the security module losing its memory possibly because my battery had been flat for a while then that could affect the immobility of the car by making the ECU dead as well.

The inertia switch is clicking ok but does that mean that it is not affecting the ECU being dead or might it need to be re-activated as I believe it can be by pressing a black rubber button on the top?

I am not sure if the security module is behind the petrol filler at the left of the boot and under the carpet as i have seen mentioned as I cannot easily see it on first inspecion of pulling the carpet back.

Is it likely that the central locking is affected in any other way on its own bearing in mind that the car has been standing in an attached garage for the last 6 months.

It is a question of whether the two are linked as a fault as I reckon that easily could be or whether there are two seperate faults.

I am not quite sure how best to proceed.

[jeffersonice]

I have checked the inertia switch and all the relevant fuses and the ECU looks ok and dry but I haven't looked inside it at all.
The starter relay and the ECU relay and all wiring and other relays behind the headlights and that front area seem ok.
The security module is not under the trunk fusebox as some suggest so I guess it must be on the left hand (nearside) of the trunk under the carpet and if it is behind the petrol filler tube to the tank then it is rather difficult to get to and certainly to remove.
There does look possibly like something between the petrol filler and the outside body of the car.

I am not sure if there is any benefit in trying to remove the Security Module as opposed to having a diagnostic check on it to check the memory on the chip and if needed have it re-programmed.

Could the immobilisation and the central locking not working both be caused by faults around the ignition switch please?

I welcome any further help and advice please re these points. Many thanks.

Jeff.