S2 Xantia Activa - immobiliser probs

wheeler · Post by **wheeler** » 22 Jul 2011, 22:38

Mike, I think the data you have for that fuse 17 must be for a mk 1 as thats the alarm & central locking fuse on a mk 1.

superloopy · Post by **superloopy** » 23 Jul 2011, 11:55

Thanks people for the replies .....

There ARE pin numbers (1,20,38) just visible on the ecu itself (richard,ta!) and i'll be able to check the pinouts as suggested.

Jim, yes a fault finding mini guide would be a good starting point, I do have a test light and a multimeter but am finding it extremely difficult to interpret those elctrical diagrams, for example AA+ BB+ et al, 2V NR, 15V BE et al, what does all of this mean? Or do i not need to know at this point in the fault finding, 'ignorance is bliss' sort of thing

Wheeler, I may be well out on my fuses although the info came from a citroen service book headed 'Xantia Electrical diagrams RHD 1998 model year RPO 7483 ->', my car is a 1998 S2 RPO 8067. Correct or not?

Appreciate it if anyone has a definitive list of the fuse layout on the car as it should be, Jim: no mention automatic gearbox fuse anywhere on my layout?? It just says F17 is the alarm control unit, F27 being the central/deadlocking 3o amp fuse. So maybe a fresh list would be a good starting point

<edit> anyone able to identify pin1 on the bitron relay, which i now know as the double injection relay, wheeler, ta!!

addo · Post by **addo** » 23 Jul 2011, 12:05

OK, some diagram basics.

The "V" numbers are the number of possible pins on a plug/socket. EG, a 15V plug has up to 15 pins, although some positions may be empty ("unpopulated" is the jargon).

The two letters thereafter are the colours. BE blue, NR black, VE green, MR maroon, GR grey, BA white, JN yellow.

Numbers on the diagram wires near the plugs (eg; 1351) are stamped repeatedly on the wires however it seems inconsistent which order they are interposed with other factory identifiers. Once you think you've found the correct plug, start noting a few of the codes to crosscheck.

xmexclusive · Post by **xmexclusive** » 23 Jul 2011, 14:31

The double injection relays usually have the internal wiring diagram embossed on the case. Pin numbers are typically marked in the plastic outside the pins. There are a good number of variations in the wiring of these relays. Each type has its own part number eg 2401xx.
Correct type has to be used. Found that out the hard way.

John

superloopy · Post by **superloopy** » 23 Jul 2011, 15:19

Thanks all, every little helps as they say. I'm hoping to get a move on this tomorrow.

Just as an aside, the lexia references a harness tester function. Anyone seen or used this, I'm assuming it came as an expensive add on to the workstation. Maybe it could have helped. What exactly is it? My lexia came with so many cables that I haven't really got a clue about, perhaps I have the functionality without realising .... I recently discovered that I DO have a battery cable to power the unit after months of using it by running it off its own internal battery for 10mins at a time, doh!!

DickieG · Post by **DickieG** » 23 Jul 2011, 15:35

superloopy1 wrote:Just as an aside, the lexia references a harness tester function. Anyone seen or used this, I'm assuming it came as an expensive add on to the workstation. Maybe it could have helped. What exactly is it?

Its an additional tester on top of the standard Lexia either by way of a manual tester looking similar to an old telephone exchange or an automatic one as fitted to Lexia 2 in the basestation. You then need numerous harnesses dependant upon what you are testing, it allows you to test the wiring/resistances etc relevant to the ECU. You then need the original Citoren workshop manual for the relevant ECU to see what the original values are, useful as it allows you to test items which may be suffering from a duff connection that doesn't show up when you pull the connector apart. It also allows you to test every component directly from the ECU. I have both versions of the harness tester and a full set of leads but have rarely if ever used them other than 'playing'.

superloopy · Post by **superloopy** » 23 Jul 2011, 17:47

DickieG wrote:
superloopy1 wrote:Just as an aside, the lexia references a harness tester function. Anyone seen or used this, I'm assuming it came as an expensive add on to the workstation. Maybe it could have helped. What exactly is it?
Its an additional tester on top of the standard Lexia either by way of a manual tester looking similar to an old telephone exchange or an automatic one as fitted to Lexia 2 in the basestation. You then need numerous harnesses dependant upon what you are testing, it allows you to test the wiring/resistances etc relevant to the ECU. You then need the original Citroën workshop manual for the relevant ECU to see what the original values are, useful as it allows you to test items which may be suffering from a duff connection that doesn't show up when you pull the connector apart. It also allows you to test every component directly from the ECU. I have both versions of the harness tester and a full set of leads but have rarely if ever used them other than 'playing'.

Where does the harness tester component 'live' on a Lexia 2 and what does the harness tester leadset look like i wonder?

DickieG · Post by **DickieG** » 23 Jul 2011, 19:03

superloopy1 wrote:Where does the harness tester component 'live' on a Lexia 2 and what does the harness tester leadset look like i wonder?

It lives under the platform the Lexia sits on, the connectors are on the back, two large round sockets which connect to a 'Y' shaped lead that connects to another lead such as one of these for instance;

superloopy · Post by **superloopy** » 23 Jul 2011, 20:37

Thanks Richard.

I've got a harness tester

, i've just checked.

Now then, is this going to be of any use to me in the longer term given that i've also got a rat's nest of cables which mean little or nothing to me and i've got no ecu manuals that you refer to.

Any info on what to expect if i connect it up and how do i start playing with it, seems a nifty little gizmo to have if i can get some knowledge to go alongside. The cables do have reference numbers on them, any chance you have a cross reference to what's what?

Not that i'll be playing with it just yet, maybe after i resolve this little immobility problem which i'm sure i can get my head around with the help of you forum guys

superloopy · Post by **superloopy** » 23 Jul 2011, 20:42

addo wrote:OK, some diagram basics.

The "V" numbers are the number of possible pins on a plug/socket. EG, a 15V plug has up to 15 pins, although some positions may be empty ("unpopulated" is the jargon).

The two letters thereafter are the colours. BE blue, NR black, VE green, MR maroon, GR grey, BA white, JN yellow.

Numbers on the diagram wires near the plugs (eg; 1351) are stamped repeatedly on the wires however it seems inconsistent which order they are interposed with other factory identifiers. Once you think you've found the correct plug, start noting a few of the codes to crosscheck.

Thanks addo, partially understood, and Jim: yes, BOL comes in v.useful, why didn't i check that first? Maybe your basic 'basics' guide can include that as 'Step 1'

I'm getting there slowly

, very.

DickieG · Post by **DickieG** » 23 Jul 2011, 21:53

superloopy1 wrote:I've got a harness tester , i've just checked.

Now then, is this going to be of any use to me in the longer term given that i've also got a rat's nest of cables which mean little or nothing to me and i've got no ecu manuals that you refer to.

Any info on what to expect if i connect it up and how do i start playing with it, seems a nifty little gizmo to have if i can get some knowledge to go alongside. The cables do have reference numbers on them, any chance you have a cross reference to what's what?

Have you got the 'Y' shaped harness? You need that to connect the tester to the relevant breakout harness then connect that to the ECU. IIRC you'll need a 55 pin harness for an Activa which without checking I think has a blue block? The relevant engine manual will have around 10 pages of info. Let me know if you have the 'Y' harness and the one to connect to your ECU and I can dig out the relevant info from the manuals.

superloopy · Post by **superloopy** » 24 Jul 2011, 16:51

wheeler wrote:Do you have a test lamp with a proper filament bulb (not an LED type) ?
This would be best to use along with a voltmeter. A voltmeter can show 12v but not enough current to light a bulb.
You want to be checking for a permanant battery live feed at pin 18 of the ECU & an ignition feed at pin 37.
You want to check pins 19 & 24 for a good earth. Remove clean & refit earth point MM03 which looks like its on the front of the gearbox from the pic but not very clear.

Right ... start made on injection ecu. Pin 18 has a positive feed, pin 27 (not 37, i'm assuming that's a typo, wheeler?) has a switched ignition feed and both pins 19 and 24 a negative. Is that ok?

I've got readings for all 55 pins, should i post these up?

What's confusing me is that a few give no reading of any sort despite the pin being present, for example pins 9 thru 14 amongst a few others. I've not got the knowledge (yet) to ascertain whether they should give a reading of any sort, perhaps someone could take a look at Jim's circuits and let me know what they think?

I've got similar reading for the double injection relay but as I still cant work out which pins are which i've posted up the physical layout readings then someone in the know may be able to map them to the pins, theres only 15 of them.

They double injector relay is laid out in a top row of 8 pins and a lower row of 7 pins the middle one of which is empty.

My readings were - top row left to right -

No reading
negative (which tested positive on ignition on which i dont understand why?)
Switched ignition positive
Negative
No reading
Negative
No reading
Permanent positive

Bottom row left to right -

Negative
No reading
Permanent positive
Empty - no pin
No reading
Permanent positive
Permanent positive

Anyone able to translate any of this for me, much appreciated, best of luck

<Edit> Still need to locate MM03 earth and check this out if anyone has any ideas?

wheeler · Post by **wheeler** » 24 Jul 2011, 20:13

superloopy1 wrote:Right ... start made on injection ecu. Pin 18 has a positive feed, pin 27 (not 37, i'm assuming that's a typo, wheeler?) has a switched ignition feed and both pins 19 and 24 a negative. Is that ok?

Not a typo Pin 37 (wire no 1217) should go live with the ignition switched on, gets powered by the double relay. Are you checking this with the ECU plug disconnected ? as that will cause you not to get a feed there as the ECU has to switch the relay. This is where a breakout box & apropriate test harness comes in handy that DickieG was talking about.
If you need to you can either peirce the wire insulation to test of take the cover off the ECU plug so you can test the pins with the plug still connected.

superloopy · Post by **superloopy** » 24 Jul 2011, 20:18

Ok, yes with the ecu plug disconnected. Reckon i'm stumped now then

.

Any ideas on the relay pinouts?

superloopy · Post by **superloopy** » 24 Jul 2011, 20:55

DickieG wrote: Have you got the 'Y' shaped harness? You need that to connect the tester to the relevant breakout harness then connect that to the ECU. IIRC you'll need a 55 pin harness for an Activa which without checking I think has a blue block? The relevant engine manual will have around 10 pages of info. Let me know if you have the 'Y' harness and the one to connect to your ECU and I can dig out the relevant info from the manuals.

Richard

I've checked and do have the ecu breakout box, numbered 4126-T 55, and it's blue!

Not so sure about the 'Y' harness though, what's that like? Is it in your picture?

I've got a lead about 3metres long which is double ended, yes?

I'd appreciate a picture so that i can take another look in the rats nest of cables

What facilities does the harness tester give you? You'll see from the previous post that I haven't got a clue how to go about this but i am learning slowly. I can even make sense of the circuit diagrams moreorless