Codes/computer are really frustrating :)

[Citroenfan]

Something interesting (and frustrating) just happened with our 92 XM. After a quite pleasant morning drive a few hours ago I went out to move the car to check tire pressures. Turned on the ignition and both the 'red' and 'green' LED's on the code input panel lit up….Could not input the 'start' code for the engine computer and, of course, the car would not fire up. Additionally I noticed on the control panel LED's that the symbol for the Lamba sensor was missing.

Got out the code reader (thank you XM Club) and tried to get code readouts - keeping in mind that this is a 12 valve V6 petrol engine. First tried using the 'green' plug (one I have used previously) - no codes. Tried a couple of times - nothing. So switched to the 'gray' plug. Got a start code of 12.

In succession (did twice) got the following codes:

21-22-24-25-33-34-42-43-44-45-51 and then the end code of 11.

I did talk with Hein Gijsen (fellow Cit owner - CX's- and professional mechanic who has worked on this car for the previous owner) and he reminded me that the computer in the car is a replacement unit supplied some time ago by Andre Pol and needed 1-1-1-1 input to access. Which has never been a problem. And I have contacted Andre with all of this same info.

At this point I have absolutely no idea what is going on. I did disconnect the battery for some 15 minutes (which should have wiped all codes from the computer memory). That did not solve the problem.

Anyone have any ideas at all

Take care and thanks,

Steve Hammond

[xmexclusive]

Hi Steve

Red and Green lights on the keypad often indicate a comms failure between the keypad and the engine ECU.
This can sometimes be due to a poor contact developing on the connectors.
So check contacts, spray with a bit of electrical contact fluid and refit.
Key pad connector and ECU connector.
A wire fault is less likely and more difficult to track down.

A second cause of Red Green lock-up is loss of power supply to ECU or keypad.
Earths and positives are needed as it is a chain of data not a single signal.
So check the supplies and earths.
As the ECU starts up it sends a data string to the keypad.
Key pad in good order puts up the red light and waits for key code entry.
It then sends back a modified data stream to the ECU.
The ECU decodes this and compares the result with the last two start codes used.
If either match the ECU releases the Immobiliser and starts the engine.
It also "shuffles" the start codes stored.
Code number in the "old" code store is overwritten by the code currently in the "start" store.
Code just used is written into the "start" store.

0001 and 1111 are special codes used by Citroen for setting Immo out of use.
An ECU will have been programmed at factory to use one OR the other of these number codes for this function.
So the number not used by that particular ECU becomes one of the general security codes available on the keypad.
The change to 1111 was made because 0001 became widely known.

The fact that you have different version ECU's one using 0000 and one using 1111 is not relevant to your present Red Green lit problem.

Using a different colour code plug on a MK1 XM means you are talking to a different ECU and not the Engine ECU.

If the ECU plug is now dead and cannot be read then I suspect the Engine ECU has lost one of its power supplies or earths.
Missing Lambda light also suggests the engine ECU is not completing its start-up tests correctly.

John

This post has been edited by xmexclusive on February 05, 2017 04:11 pm

[Citroenfan]

Hi John,

First off - thanks for the quite helpful and very quick reply. A bit of history on this car. One of only 52 brought into the US in the early 90's. Pauline and I are the third owners. Car, has had from what I gather, a hard life mechanically. The hydraulics are not a problem for me as I have owned and driven hydraulic Cits since the early 60's. I repair and rebuild pumps/suspension spheres-accumulators and steering racks for other Cit owners (in the LA area and else where) for quite a few years. Was not real happy with the seal kits I could get over here, so started machining my own Teflon seals and sourcing the 0-rings from good, local supplies. But that is an whole other story .

CPU - replace a few years ago when the original stopped working - at least that is my understanding. Replaced with a unit sourced from Andre Pol in Holland.

Engine - also replaced with a good used one from Andre. Original badly damage when a coolant house broke and car was run hot. Repair shop found out it was cheaper to just replace than try to repair. Also a few years ago.

Engine Diagnostic plug - has not given codes for some time. Car ran just fine. My problems with the O2 sensor discussed in another thread. And it was during that episode that that plug stopped providing info. Along that same thread - the only other diagnostic plug I can find is the ABS plug (grey) that only has one wire going into it under the CPS cover/box - and the one I used this time.

Current Problem(s) - what I have noticed the past few weeks of usage. After about 1/2 mile or so of driving after start up - I would get just a hint of engine surge/lack of throttle response at partial throttle. This would last for maybe 15 seconds and then disappear. Would not come back until engine compartment was cold again (overnight). That, given your excellent ideas, leads more credence to the very real probability of bad electrical connectors/connections

Got a lot going on right now so will not be able to get to all of those connections until Tuesday at the earliest. Hoping the weather will co-operate

TIA,

Steve

[Citroenfan]

Well as was suggested here, by Andre, Hein and others it did turn out to be some 'duffed' connections. Not sure which one as I just took a spray can of electrical contact cleaner and starting with the computers and every other plug I could find in the engine compartment, cleaned thoroughly with small brushes. Plugged all back together and car fired right up . Now need to attack all of the ABS connections to see if that solves the problem of the ABS being 'finicky' - sometimes being on and sometimes going out of circuit.

Thanks all - owning an XM in the US does leave one feeling a bit lonely . And I am not use to a Cit with all of these bloody connectors and computers. Just give me a 2 barrel Weber and an assortment of jets and A/C tubes and I am just fine, thank you very much........

Steve

[xmexclusive]

Hi Steve

Bendix ABS on an XM can be hard work.
My best logic is to split the fault finding into separate parts.

First note and record what the ABS does.
That can help decide where and what to test for fault finding.

Static tests:
When the ignition is switched on the ABS light should blink twice and then clear.
While doing this test all the elements of the ABS are checked twice.
ECU run up and power supplies checked, ABS relay checked, ABS block electrovalves checked then finally the resistance value of the four ABS sensors checked against permitted values then finally it checks the fault ECU record for faults so serious that the ABS is locked out of use.
If any of these items fail the test the ABS light turns on and stays on.
Reading the ECU fault record and clearing it will remove a serious fault lockout but only until the faults mount up again.

Dynamic tests:
We now have a ABS system that passes the Static test and clears the ABS light.
When the car is driven the ABS system will monitor performance, make fault records and compare those records against a table of permitted fault numbers and combinations of faults.
When a fault limit is reached the ABS light comes on and the ABS switches out of use.
We are now in the area where the fault(s) are most likely to be intermittent.
Something that means simple testing may miss the fault.
Reading the ECU is the best way with this as all the intermittent faults will be recorded.
Note the faults, clear and the record what comes back.
This will drill down to the actual problem(s).

That should let you check and report what your ABS is actually doing.

Best regards

John

This post has been edited by xmexclusive on February 13, 2017 12:10 pm

[xmexclusive]

Hi Steve

Checked again your starting post.
The ECU that you read was the ABS ECU.
21/22 are ABS relay faults.
24/25 are NSR/OSF sensor faults.
33/34 are NSR/OSF sensor signal faults.
42/43/44/45/51 are all ABS block electrovalve faults.

These will have been building up over a long time.
Try the Grey test plug and see if you can reset and clear the faults.
That should tell you what are the current real faults.
Then run the car a bit and read again to see what comes back.

Check the code numbers marked on your ABS ECU.
The code you are looking to check for is either:
S101 320 001 or S101 320 002.
Tell me which you have.

A list of ECU plugs for the Mk 1 V6:
Green plug - Engine ECU.
Blue plug - Suspension ECU.
Black plug - Climate control ECU.
Grey plug - ABS ECU.

I can supply fault code numbers for those if you need them.

John

This post has been edited by xmexclusive on February 13, 2017 02:17 pm

[Citroenfan]

Hi John,

Thank you for all of the info. Will not have time today, but should in the next few days pull down all of the fault codes from the various circuits. Have a few other things I need to tack down, a rear window winder that has not worked since before we acquired the car as well as a, now, non functioning, interior fan . Now that the weather here in Southern California as dried up a bit, I need to also get back on my re-assembly of my 72 DS.

Take care,

Steve

[xmexclusive]

Hi Steve

Please confirm that the rear window winders are electric.
For the fan I assume you mean the blower fan that feeds all the dash vents.
Is your car RHD or LHD?

John

[Citroenfan]

Hi John,

Blower - yes the one in the dash . Rear windows are electric. LHS works a charm as do the the fronts. Just the RR does not respond.

LHD car - imported to the US via Andre Pol and Dave Burnham. Our understanding was that 52 cars, in total, were brought in. 2 of them were crash tested to satisfy our DOT regulations. The other 50 were sold. Not sure how many are left on the road at this time. When Pauline and I saw Dave last June at the big Cit gathering in upstate NY (Drive She Said) he was almost 'pleading' with me to build a very large shed in my back yard so I could relieve him of all the smashed bits and parts left over after those tests .

If anyone has a D series that needs hydraulic help, please feel free to have them contact me. I rebuild pumps / suspension spheres / 3 groove (AC) water pumps and have lots of info on all of that stuff.

Take care and, again, a big, big Thank You for all of the help as well as moderating a really great site.

Steve

[xmexclusive]

Hi Steve

Thanks, the answers help focus me on what to suggest.

Quick first test is to swap the rear window switches between the rear doors.
Poor contact on the switch connectors is a common fault.
If that does not work then swap back and try the good window.
Listen for the sound of the motor drive.
Then try the non worker and listen for the same sounds.
Broken wire and you usually hear the motor.
I try not to send people into the door unless it is essential.

I need to look up about blower fans on LHD XM's.
From memory there are a few differences from the RHD ones I deal with.
There are a few stock blower problems and most have fairly easy fixes.

Which type of climate control does your XM have?
Digital panel or rotary knobs and slider.

John

[Citroenfan]

Hi John,

Instrument panel is all push button (s) - car is equipped with an 'automatic' climate control. One just sets in the interior temperature you wish to maintain and the system is 'suppose to maintain that automatically'.

I switched out the rear window toggle switches - no change. And I cannot hear any indication that the non functioning rear window motor is trying to do anything.

Take care and again, a big, big thank you.

Steve

[xmexclusive]

Hi Steve

With the rear window I would now suggest you test the motor.
If you take the switch out its plug has five contacts.
The outer pins (1 & 5) go direct to the winder motor.
A car battery plus fly leads (spade connectors to crock clips) can test the motor.
This gives a direct connection so fix one of the leads and dab the other on the battery.
Reverse the polarity for the motor to go the other way.
If the motor runs but not the glass we are looking at a broken drive cable.
If the window moves correctly both ways then check and clean the door electrical connector.
Then do the same for the console window switch.
If none of that clears the fault then you are looking at a wiring fault.
If you send an email address to chrisatpegasus@aol.com I will send back a wiring diagram (modified Citroen specifically for DIY fault finding.

John

[Citroenfan]

Hi John,

Sorry about the delay - just to much going on here. In the process of getting my 72 DS 21 BVH back on the road with all new interior and body panels (only has a bit over 640,000 miles on the chassis ).

Heater fan motor turned out to just worn out. Brushes worn down to the proverbial nibs. Are there any decent used units out there or is the actual motor assembly available sans exterior housing and rectifiers? Cannot get the unit re-brushed over here as no one has the proper parts. And even if they did doubt seriously if they would want to touch it in any event

Rear Window motor - low on the list of priorities. Am getting an engine code of '13' and '51' - checked the 02 sensor and am getting voltage fluctuation between 0 and 1 volt when hot. So it may be interconnected with injection air temp sensor. Had a bit of problem getting the car passed our bi-annual smog check a few weeks ago.

In either case - really just want to thank all of you for all of the help with this beast Having a couple of D series cars, and SM, an 85 2CV as well as the XM keeps things interesting.

Take care and thanks.

Steve

[xmexclusive]

Hi Steve

A little while ago Gabor did a guide to fan brush replacement.
Complete with photos in the self help on the other place.
You may well find it on Gabor's own website.
Original brushes can be bought on ebay.
There are a few working fans that I could source.

John

[Citroenfan]

Hi John,

Thanks

If by the 'other place' you are referring to the other XM forum - cannot access it. Have tried to set up an account with them to no avail. So just gave up - that is why I am here......

Tried to locate Gabor's web site - no luck. Only thing I got was a Google reference that went nowhere.

(Next Morning ) - Well I was finally able to get into the 'other site' - old brain forgot that I had screwed up my 'user name' - being 71+ and hitting ones head hard against a solid object occasionally works. Located Gabor's link to his web page. Info there is on the size of the brushes - nothing else. OTOH looking at the unit, seems a fairly straight forward job. Now just to fine time to do this little giggly chore in between a couple of D steering racks that need complete rebuilding as well as spheres to recharge and two sets of LHS units needing complete refurbishing. So why is it that as we age time seems to speed up???

As to the fan motor - when you have time let me know. Would be good to have a spare in any case

(Saturday Morning) - by searching a bit on the 'other site' I found his picts on replacing those brushes. Did a search on EBay UK and found a couple more suppliers of, what looks like, brushes that will work. Just waiting back to hear from each on actual sizes. OTOH would be good to have a replacement unit, on hand, just in case..... Also located a company in France that has new, in the box, Valeo units for about $125 (US). Have inquired re: shipping to Los Angeles.

Take care - and again thanks for all the help and all of you just being here.

Steve

This post has been edited by Citroenfan on April 15, 2017 05:24 pm