1998 XM V6 24V Exclusive:

geofwct

New member
Tadpole
Joined
May 26, 2012
Messages
11
Location
Sydney
Anyone with knowledge, please assist: Following some routine maintenance I attempted to start the engine but although it cranked okay, it would not start. I then noticed that neither the red nor green lights were lit on the coded anti-theft device in the centre console. My suspicion has therefore fallen on that. The device has the 'S' and 'C' buttons. Any ideas on why it appears to be dead? Geoff 0478 915 690
 
did you have the battery disconnected ,during your maintenance ,have you tried locking the car with the key then unlocking with the key ,i would sagest leaving the drivers window down when doing this to ensure you dont get locked out ,are you using the usual key ,has the key battery been replaced .if so there is a procedure to be followed to re program it to the car ,someone on here will no drought know .
 
I don’t think there’s a connection between the key and the immoblizer keypad. You can start an XM with a key with no fob attached. Given the absence of lights on the pad, I would start looking at fuses – the ones under the bonnet near the battery, in particular. Check F1.

If this doesn’t fix the problem and you don’t get other ideas here, try the UK-based Club XM.
 
Hi gents,
Thanks for the ideas but I'm still stuck. The battery was disconnected throughout dealing with top-end oil leaks and anyway, I have fitted a new battery. All fuses are good and I have lifted up the engine bay fuse box to check the wiring - all good.
One thing I did early on was disconnect the computer because I wanted to renew the plastic sleeving on various cables. Would that have had an effect? Electrically, the car was dead at the time.
 
Try entering 0001 into the immobiliser keypad.

If that works, I will tell you all a story.

Cheers, Ken
 
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Thanks Ken but that didn't cure the problem. I think I've identified the double inj relay so I am going to try swapping that over from another car to see if I can isolate the problem.
 
The immobiliser works by not pulling in the injection/ignition relay. The car cranks OK, the engine ECU just doesn't allow power to the injectors or fire the plugs until the right code has been entered into the immobiliser.

Are you getting all the correct warning lights on the dashboard? A faulty fusebox could also lead to this problem.

I have found that lots of battery problems can end up in the immobiliser forgetting its settings and reverting to factory defaults.

Cheers, Ken
 
you got in park when you are trying to start it?
not being a smart alec, i've braindeaded on that one before or discovered that the stick is poised not quite in P and not quite in R.

on a serious note, disconnecting the battery will have no effect on the immobilizer.
i have a battery disconnect on mine to stop it going flat and no problem when i turn it back on again.
also we had one disconnected from its battery for 6 months to do a head gasket and no problem again when we fired up the first time.

has to be some kind of other fuse, relay problem?

don't believe we disconnected the ecu in the head gasket job, we had it up and out of the way but kept the loom connected.
not sure what that would mean to disconnect it. pretty sure that was the case as i recall always having to work around that mass of wires which runs across the top of the prv engine from one side of the engine bay to the other. i seem to recall when all was done and we went to fire it up it would not fire. can't remember now if it cranked and would not fire, or if it would not crank. i think it was cranking but it was a couple of years ago so memory is faulty. anyway, mechanic walked over and jiggled one of the relays in the front of the engine bay next to the radiator and the engine fired into life. i think we were cranking it because my memory is he just walked over jiggled and we were in process and suddenly bam, we had an engine running again and he walked away with a grin on his face.

that particular car had had work done on those relays that our mechanic was familiar with as a fix. it was the green car that belonged to a member here for a long time. i no longer co-own that car so i can't be precise about the details of that relay fix/update but i think it was a standard kind of fix that was done with a lot of xms to improve the reliability of those connections and relays. these days i am running a 99 model with the later engine. that one i have a switch off on the battery. this presents no problem for the ecu when the battery is switched off.
 
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I checked over all the wiring and found a plug/socket not connecting. This is located on the right hand side of the engine top, about 2 inches up from the oil level dipstick. I found the female plug was slightly damaged in that one of the short sides of the rectangle was broken, allowing one leg of the security spring to jump inwards. This prevented engagement of the plug to socket. I managed to prise the spring out (it's a strong bugger) and get it into its correct location before joining the electrical connection with a resounding 'click'. The engine then started! It was a bit lumpy at first, possibly due to the excess petrol vapour that had accumulated during the multiple starting failures, and which could launch the space shuttle. All is now good....except for the heavy oil leak that I thought I'd fixed! Many thanks to all of you who offered advice. I have learned a lot and I hope others will learn from my experience.
 
Great news Geoff! Would be great to hear a bit more about your car - how long you've owned it, how far you've driven it, what still needs fixing etc...

For example - have you replaced those pesky bushes either end of the power steering ram?
-
Edit - have just seen your "For sale" ad - I guess that makes it even more interesting to know a bit more history. Is this car that you have just fixed the one that you are selling? I notice that this thread refers to "1998 XM V6...", while in the ad you have specified "2000 XM..."

Cheers

Alec
 
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I checked over all the wiring and found a plug/socket not connecting. This is located on the right hand side of the engine top, about 2 inches up from the oil level dipstick. I found the female plug was slightly damaged in that one of the short sides of the rectangle was broken, allowing one leg of the security spring to jump inwards. This prevented engagement of the plug to socket. I managed to prise the spring out (it's a strong bugger) and get it into its correct location before joining the electrical connection with a resounding 'click'. The engine then started! It was a bit lumpy at first, possibly due to the excess petrol vapour that had accumulated during the multiple starting failures, and which could launch the space shuttle. All is now good....except for the heavy oil leak that I thought I'd fixed! Many thanks to all of you who offered advice. I have learned a lot and I hope others will learn from my experience.
good stuff mate.

sorry to hear about the oil leak. i remember putting the sump pan on the green car three times. just kept leaking.
thank christ the timing chain cover didn't. what a screw up that would have been if it did. i recall it was a three man job to get that back on doing a head gasket with engine in car. one to hold the cover with its wet gasket. one under the car feeding in bolts and one on top feeding in bolts. would have been a nightmare trying to do that as a one man job. impossible even? two guys - borderline possible.
 
Hmmm...I've had the sump pan off 3 times as well. I've done the camshaft covers 3 or 4 times. I have a heavy leak from behind the plastic backing of the timing belt/camshaft drives, the plastic extending right down to the front crankshaft seal area. I wonder if that is leaking. I am now considering lifting the engine out of the car to fix these persistent leaks.
 
Only did my 406 SV sump twice :) - 2nd time I reinstalled the silicon strip (original?) and held it in place with new silicon gasket goop. Let it start to go off, then installed sump with bolts essentially finger tight. Torqued up next morning. So far so good.

If you are getting oil in the spark plug well below the filler cap then it will be the filler cap not sealing properly. Supplied invoices for my Xm showed that it had a new oil filler cap < 5 years ago. Seal had gone hard and cracked in half when I disturbed it. Replaced it with a couple of large O-rings (smaller fits neatly inside larger).
 
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