XU10J2 crankshaft position sensor ?

Mosser · Post by **Mosser** » 02 Mar 2007, 11:35

Back again with more problems with my car !

Its a 1998 2.0i petrol Citroen Synergie

It now wont start at all, there is now no spark at all, and tracing back through the coil, there doesnt appear to be any signals coming into the coil pack at all, and i'm thinking that the crankshaft position sensor has failed, but the trouble is that i cant find it !

does this XU10J2 engine even use a crank position sensor ?, or could it be getting all its timing information from just a cam position sensor ?,

Either way, does anyone know where these sensors might be on the engine ?

I've got an old haynes book of lies for a peugeot 406 that uses the same engine, and its pretty useless on all counts really

I suppose it could also be an ECU faliure too ?, is there any test for this ?

Thanks

Post by **CitroJim** » 02 Mar 2007, 12:06

Hi Mosser,

The Crank Position Seensor is located on top of the gearbox bellhousing. It picks up the teeth behind the ring gear on the flywheel for timing.

Three possibilities, Sensor, as you say, the ingniter, a standard, common Bosch job located somewhere on the bulkhead or the coil itself. Favourite for me would be the ingniter or the connections between the components.

There may be a supression capacitor connected between the coil plug and the thermostat housing. It might be short-circuit. The engine will run without it for test purposes but if it is absent for any length of time, you'll get funnies due to ignition interference getting into the ECU.

Mosser · Post by **Mosser** » 02 Mar 2007, 13:08

That was a quick answer, and exactly the information i needed !, thanks

I have now bypassed the capacitor, and it made no difference, there's still no spark,

And the only connector i can find on the gearbox housing is towards the front (inlet manifold side) of the engine and is about 4" along the gearbox from the engine/gearbox join and is a white 2 pin connector, and when tested with a multimeter, it is open circuit, is this right do you know ? (or anyone else)

I'm not too sure what an igniter is, can you describe its shape ?, or what its job is ?

thanks

Mosser · Post by **Mosser** » 02 Mar 2007, 13:11

Also, i couldnt find any 12 volt supply in the 4 pin connector that plugs into the coilpack ?, is that right ?, i tested it with the ingition on, and there's no voltage between any of the pins, but i'm wondering if it only provides power when it needs to create a spark ?, but have no idea whether its even safe to crank the engine with a meter on the 4 pin connector (possible ECU damage?) or what voltage to expect on it ?

Post by **CitroJim** » 02 Mar 2007, 14:28

Hi Mosser,

No worries...

I'm not sure how you bypassed the capacitor. I trust you did not literally bypass it by putting a short across it! Test it by disconnecting the thermostat end and leaving it disconnected. If you now have sparks it'll be because it was short-circuit.

The igniter is the little oblong, nearly flat box that you'll find on the other end of the loom conncecting to the coil. Its proper title is Ignition Amplifier and its role in life is to amplify the ECU ignition signals to a level sufficient to fire the coil.

The connector you have found is (I guess) the reversing light switch. The CPS sensor will be on the edge of the bellhousing so that it can look down at the flywheel. It is either on top or toward the back near the diff. I can't see it on mine due to all the turbo gubbins and hydraulics being in the way. Also, don't mistake the knock sensor (green plug) for the CPS.

I'd not expect to see +12V at the coil given your problems and in any case you'll only see any voltage around there with the engine running as it'll be pulses and these will not be present with the engine stopped.

Do you see the tacho move when attempting a start. Generally if you see no "kick" during a start attempt it's a good odds-on the amplifier is unhappy.

AndersDK · Post by **AndersDK** » 02 Mar 2007, 15:15

Errrr...

You MUST have a live +12V on one of the coil pack connector pins. The ECU or ignition module provides a NO (normally open) switch function to one side of coil, briefly closing to ground when an ignition HT pulse is needed.
If no distributor is fitted on end of the camshaft, then the ECU provides 2 NO ground pulses. One for each double HT output of the coilpack.

I'd certainly pursue the missing 12V live (when ignition switch is in drive position) problem on the coilpack connector, while the capacitor is DISconnected or REMOVED. At the same time do an ohm's test on the capacitor. It should read open circuit using an ohm meter.

Mosser · Post by **Mosser** » 02 Mar 2007, 15:52

I bypassed the capacitor by undoing it fromt he thermostat as you just said, not by shoting it out !!

could the ingition amplifier be built into the coil pack on my car ?, as there is no other small boxes between the ecu and the coil pack, the coil pack is a big black potted box with 4 ht terminals on it and a 4 pin lt connector going into it from the wiring loom, the connector on the lt side has a small black retangular box coming out of it, but its just a 2.2 microfarad capacitor that is bolted onto the thermostat housing

You right about the white gearbox connector, when i put it into reverse it is shorted out !! (Doh!)

I have now found the TDC (or crank position) sensor, it is right on the edge of the gearbox and points down at the flywheel, it has a brown 2 pin connector on it, and when i get my wife to crank the engine over, i get no voltage spikes from it whatsoever between any pins, I'm assuming its just a hall effect sensor that is detecting a magnetic pulse from the flywheel, but dont know whether i would be able to see the voltage spikes on a meter and i dont have an oscilloscope to check it with

The needle doesnt even slightly move when the engine is cranking over, and i assume from your post that this is drive from the TDC sensor ?, so i should be seeing it jumping or bouncing when the engine is turning over ?

Anders, thanks for the input, do you know which pins i should find 12V on ?, I'm guessing that it is a wasted spark coilpack, and that there is probably 2 coils in the potted box, and that of the 4 pins, 2 are used for firing each of the 2 coils, and the other 2 should be +12v and ground ?, There is no distributor on this engine at all, i think the engine picks up its timing reference from the TDC sensor, and the ECU sends a signal to fire the coils when they are needed ?

So after all this, I'm not sure whether its caused by no 12v feed to the coil, or a faulty TDC sensor!, but as its hammering it down with rain at the moment, there's not much i can do till it stops long enough for me to trace the wiring !

Thanks very much for both of your help, its very much appreciated !, and i'm learing lots about how the ignition side if a car works, which is something i have never really looked into previously!

Post by **CitroJim** » 02 Mar 2007, 20:03

Right, I've been digging into this Mosser. Unfortunately I've had to base this on the XU10J2TE disgrams as I cannot find any specific to yours.

Thanks Anders for correcting my senior moment regarding a 12V feed to the coil! yes, there is and this should be on pin 4 of the coil plug. It is fed from pin 1 of the double injection relay. Pin 11 is the other side of the double relay and this will have 12V from (I think) either the ignition switch or the battery direct. A crude test will be to link pins 1 and 11 on the double relay and see if sparks then result.

When you first try to start can you hear the fuel pump prime? That will give a clue if it is just ignition failing or a more general problem.

Pins 1 and 2 of the coil go to the ignition amplifier and I'm pretty sure you have one. It can be very well hidden, mine being low down on a chassis rail! It is such an insignificant little thing and easily missed.

A useful link to the diagrams I have been looking at are here:

http://peugeot.mainspot.net/wiring406/index.shtml

These are for the Pug 406 but they're all much of a muchness really and illustrates clearly the general functioning of the ignition side of things.

Hope that helps a bit Mossser...

Mosser · Post by **Mosser** » 02 Mar 2007, 20:16

Cool, thanks for looking all that up for me, Its still hammering it down with rain here and its dark too so i will have to wait till the morning to do that, but will be onto it first thing in the morning if its not raining as i'm eager to get my car running again

and those wiring diagrams should help loads too, not sure if the fuel pump runs or not as its very quiet on this car, but will check that too, I have sprayed a small amount of damp start into the intake directly and that didnt make any difference at all, but i did forget to open the throttle so it probably didnt make it into the engine !

I will let you know how i get on tomorrow

Thanks

AndersDK · Post by **AndersDK** » 02 Mar 2007, 22:33

So you see Jim -

You just needed a bit more time ...

Have no further info to add, good luck Mosser

Mosser · Post by **Mosser** » 03 Mar 2007, 15:27

Just thought i'd update you on my progress (basically none!)

I cant find my ignition amplifier module anywhere on the car, i/ve had it up on axle stands and been all over the subframe, looked all over the firewall and there's nothing that resembles an ignition amplifier module

Also, the fuel pump doesnt appear to run on either position of the key so i was thinking that the fuel injection relay might be at fault, but i cant find that either !!, the fuse box has a diagram that doesnt tally in the slightest with my fuse and relay layout, and there's nothing to do with fuel or ignition marked on the diagram in the lid anyway

Also, my engine management is Magnetti marelli, not bosch, so i think that my coil wiring is different to that shown in the link you posted as that shows earth on a different pin

So, basically i am stumped due to lack of information on my engine and wiring !!, i have searched high and low on the internet looking for an XU10J2 engine diagram that has magnetti marelli engine management, but they all seem to be bosch on other cars, and information on Citroen Synergies is very scarce !

Post by **CitroJim** » 03 Mar 2007, 15:45

One wishes to utter a swear word here Mosser, as I expect you have

The only XU10J2 I know to use Magnetti Marelli management was in the XM so off I went to my XM BoL and guess what, they give no engine management wiring diagrams at all, all the electrical diagrams are "Typical This" and "Typical That" but no "Typical Engine Management"

Just typical of the BoL to be useless in the area most needed I guess

I know nothing about the MM system unfortnately. If someone on here has the pukka XM manuals with proper diagrams in them then there is hope. I'm a bit preoccupied with the youngsters at the mo but when it all quietens down I think I know where on the 'net I just may find the diagram to help you. They were on another forum that deals with transplanting XU10s into other examples of PSA vehicles. Nuff said

Mosser · Post by **Mosser** » 03 Mar 2007, 15:52

Damn, thought i'd found it !, there was a small black module just poking the wiring of its connector out from under the battery, so i just removed the battery and its tray to be greeted by a second bitron unit called a PPE-GF10 which appears to be a speedo interface box

There's so many little boxes of electronics dotted round this car that its getting silly now !

I dont bother buying haynes manuals any more now, they simply dont seem to go into enough detail nowdays, 10 years ago, they were wonderful and covered all sorts of things, but nowdays, they only seem to tell you how to change the oil or wheels !!!

Post by **CitroJim** » 03 Mar 2007, 16:05

I don't know if this is of any help Mosser but I've discovered that yours may use the Magnetti Marelli 8P system.

This was also used on the TU5 engine in the Pug 106. Here is a diagram

http://peugeot.mainspot.net/wiring106/tu5j2.shtml

Coil is 1135 and the Double Relay where the coil volts come from is 1304.

On the MM systemn there is no Ignition Amp. Coil comes straght from the ECU. Fuel pump is 1210 and this is fed from the double relay.

This relay amy be very close to the ECU. It is on Bosch systems.

Here is hoping this will help Mosser...

Mosser · Post by **Mosser** » 03 Mar 2007, 16:09

Nice one, Thanks!

That looks much more like my setup, the earth is on the right pin on the coil too in that diagram !!,

But the fuel pump isnt running, and there is no 12v feed to the coil and that appears to come from the multi function injection relay, so its looking very much like that relay is at fault to me,

All i've got to do is find it now !