Citroen XM 3.0 24V- Old School Engine Diagnostic Tool! 

It sounds like the ignition timing is way off during hot start. Points towards faulty crank angle sensor. I recommend buying a cheap scope. I've got one off ebay. They are not great, but good enough to test some sensors on old cars.

The diagnostic tool might very very sensitive to voltage. Perhaps it might be worth putting a battery maintainer on the battery while using to diagnostic tool. Note I am suggesting a battery maintainer and not a charger. I have seen on South Main Autos & Pine Hollow Auto Diagnostic RU-vid channels where chargers put out too much voltage for either the diagnostic tool or the vehicles ECU to enable it to communicate. Some chargers do have a battery maintainer setting.

If you have a ground issue that can cause your connection problem. The communication is dependent on a stable low noise voltage signal. I would find the ground on the ECU and give a clean stable connection. Maybe even the power supply to the ECU. One thing to try also is Ferrite Beads on both ends of the cable can clean up noise being induced from somewhere else. Lastly, the voltage is cleaned up by capacitors on the circuit boards. There could be a bad capacitor or even corrosion somewhere inside the ECU or Scan Tool.

On a project like this even small wins mean a lot and keep you going, well done

If there is nothing else in this video, it definitely shows your persistence Seppo, that is an admirable quality. I think you may be right about grounding issues, my Trabant has quite a few problems, most are because of corrosion on the earth return wires.

How frustrating but at least you did solve one problem.

If you wish to get rid of the pin-code thing : - dismantle the keypad but leave connected - enter the PIN-code and start engine - disconnect the keypad plug - you can now start the car without pin code. Used to be a common thing back in the late 90's and, customers got tired of it. The keys would wear out and it was too expensive to change the keypad and reprogram it.

Hi, a little success each time and you will eventually win. Many thanks for the info and entertainment, from UK.

One step at a time. You'll get there.

Since the device is running Windows 98, it is from the age if decaying capacitors. It may need an electronics service check. If it is bad connection in some solderings, try keeping it warm for better contact.

Check any wiring and connections on the ECU and any wiring that passes through into the passenger compartment from the engine bay, Citroën's from that era are notorious for wiring issues with broken wires, verdigris on the terminals or water ingress in bulkhead connectors and poor connections within relays etc, i always remember the cooling fans coming on whenever there was an open circuit in the engine loom during electrical training courses at Citroën back in the 90's 😊

The AC on the XM starts automatically. It's not a malfunction, it's just like that, it's an executive car :D Source: Had two of them.

Funny story! Had a Renault25 (XM rival) many years back. The oil level indicator would not come on (of course everything checked out fine) and after lots of poking around the mindnumbing solution was a bad connection at the right front window swich. Yes... that's a true story...

I also think that a ground may be the issue. Also. When you cranked the engine. It ‘sounds’ like the timing is out. Check the flywheel trigger sensor. I am not too familiar with the distributor on these cars. Check all the sensors on the distributor as well. Resistance on a sensor or wire can cause crazy issues

If i don't look and just listen it sounds to me like bad plugs, timing not right, firing order is wrong.. I had a black 2.0 turbo XM i loved it but sometimes it would turn over and no ignition but would always start straight away with a bump start. Changed ecu and still the same. Thanks!

so the thing to look for in one of these is if the light doesn't work with the car off the alternator is dead :P

That's a job for @DiagnoseDan!

More than anything else, that old alternator will be of better build quality than anything you can buy now. Repairing isn't just the cheaper option, it's the smarter option on old cars if they are repairable. Good job.

Keep on the good job👍. Please check the crank sensor, vacuum boxes for the variable inlet manifold. One more thing that should be checked are the knocking sensors. All of the above deteriorate over time and can generate faulty signals to the ECU. Changed these on my car and it greatly improved running of the engine. Have you actually removed the earth connection points from the fenders and cleaned them? These where oxidised on the back side on my car. (Known issue on XM)

Also i would put ina new crank sensor very typical of a hot no start issue...

I know nothing of this model... but checking all powers (including 5V ref if utilized) and grounds at the ECU would be prudent. 🍀🍺

RU-vid channel involvo'd had also some hot start issues. At the end it turned out to be some leaky fuel injectors.

Hi, I recently struggled with several XM's with PRV12 engines (Fenix3 instead of Fenix4) with Lexia. Bosch ECUs (XU and ES9 engines) connect immediately, Fenix3 is a pain. When you launch connection, it tells you to shut and unshut ignition. And it does work if you do exactly that. If not it will never talk.

Hi, I also tried diagnostic on different citroen with code pad and it’s always fail. Did you saw if the red and green light were on after plugging the diagnostic tool ? (issue with my lexia on diagbox and 4120T tool, tried on xm and xantia) I saw that a key pad garage mode for maintenance exists. Maybe it’s the problem. Nice job 👍🏼 Clem

It is looking like it's a bad connection somewhere, given it'll work sometimes, and then not other times, but when it comes to intermittent faults, they're such a pig to catch in the act, and given how complex the wiring is even in an 80s or 90s car for the computery stuff, I don't envy your chasing that fault... :S

Nothing much to say. It is coming along nicely. Does the engine have a vacuum system on it, could it be this that is causing the hot engine restart problem?

That irregular cranking is weird. Maybe put a voltmeter between the engine block and battery negative to see if the voltage jumps right when the cranking seems to stop, which might indicate a bad engine-to-chassis ground connection.

Prøv at koble oplader på batteri .

Clutching at straws (and you may have already checked this) but... is there any damage to the loom by the diagnostic connector?

Early XMs were notorious because of electrical issues, most of them were caused by faulty ground connections

Check all system Groumfs,for sure!!?!?!

LM autos on youtube he will answer question. Someone on here says sounds like crank sensor, i think worn bearing in starter can give miss in cranking.armature shaft shorts out on out field

It looks like the ignition is advancing to much causing the starter to struggle turni ng the engine and your hot starting issue

What kind of ground point does it have in the engine bay? If it´s white or yellow multiconnector you must change them regardless of how good they look. Just cut the wires and put ring terminals on them, and reuse the old multiconnectors bolts as new ground points. It´s what Citroën did with the 92B model. Also, it really looks like lights in instrument goes out when the starter stalls. Again, if it has multiconnector ground points = replace immediately. It´s XM´s most infamous design flaw. No XM was more than about two years old when it was bad enough to render a recall a´la ring terminals. About the Proxia issue. In the last decades I´ve only used the "China edition" of Lexia. And on that you can mix up the polarity on the diagnose connector in the car. IIRC that cannot be done with the OEM version. But you know there are three connectors? You have one for the Fenix ECU (engine), one for ABS and one for the Hydractive suspension ECU. Just asking. I seem to be unable to learn the colours of them, but I have also seen other people just finding the wrong one, without knowing there are more than one.

Had a renault intermiten hot start would start when diconect coolant sensor. Does xm have map or maf sensors

Hello, do you have a link of an OBD/OBD2 adapter valid on the XM Phase 2? because the adapters are not all the same and don't work on them, thank you

Did you check your fuel pressure?, at mine Xm (a zpj4 24v) my fuel pump was slowly dying. It should be 3,5 bar. Sometimes it worked fine en then suddenly it wouldn’t start.

Did you monitor the battery voltage while cranking?

Alexia, make the XM work properly!... I'm sorry I can't because Windows 98 is just so last century!

There seems to be an issue with the auto exposure of your camera, the brightness in the video is constantly fluctuating. This seems to mostly affect the wide shots of the whole car, as seen for the first 2 minutes. At first i thought it was my phone, but after turning off auto brightness of my phone, the issue persisted And Citroen XM is a criminally underrated car.

Husk altid oplader på batteri når man bruger diagnose værktøj

It all seems to ne pointing to the crack pick. More so because it worse when it is hot.

Ignition module???????

Another example of why all these computer controlled cars have/will cease to exist

1st I think 🤔

Det lyder altså som om det er noget omkring noget tænding når den ikke vil starte. Har du målt omdrejningsføleren ud. Den sidder tit og måler på svinghjulet Når du drejer nøglen skal omdrejningstælleren gerne røre på sig. Det ser det ikke ud til den gør på filmen. Føleren kan godt være varme følsom.

I had a Sagem brand mobile phone once, worst phone ever!