Starter Diagram

[kingjafad]

Update2:
So It seems Lexia has some really helpful info built into it. I have found a load of wiring info. So on the 6wire connector;
1. Earth
2. 5v feed for position sensors
3. Position phase V
4. Position phase U
5. Position phase W
6. NC

Other end of the cable;

Big plug on StopStart ECU
G3. Earth
K5. 5v supply for position sensors
E4. Position sensor Phase V
D4. Position sensor Phase U
F4. Position sensor Phase W

Edit: looking at the diagram from Marc - there is a disparity on the earth and 5v pins - the diagram on the 1st page shows pin1 going to D2, and pin2 going to K3 - either way, it should be simple with a multimeter and bulb to test the ground and 5V whichever pins they are on - going to do that later when I get to where the car is located.

There is a statement in the Lexia documents;
'In Starter mode, the stop start ECU has to know the exact position of the reversible alternator rotor relative to the stator. In the event of a fault in one or more of the reversible alternator rotor position sensors, it is impossible to start the engine' ------ well, not technically impossible, but then the author of that probably didn't expect to deal with someone like me who considers it a challenge.


Just putting it on here incase the story helps others in years to come.

[kingjafad]

Update:
Just checked the 6 pin plug on Reversible alternator -
Whilst unplugged, on the wire end (from ECU) with the ignition turned on.
1. Earth is good
2. +5V DC is good
3. Sensor W +5V DC (not sure if that is to be expected as its not even connected to the alternator at this point)
4. Sensor U +5V DC same as above
5 Sensor V +5V DC same as above

When i get a chance, and a better view, ill see what the resistance is between 3,4,5 and 1 or 2 - Not sure if each sensor is supposed to just give a simple DC voltage but my guess would have been that they may be grounded through inductive resistance which would drag the voltage on each pin down depending on the position of the rotor/stators. I'll also back probe 3 4 5 and try to move the alternator position a bit and see if readings change. (Just in the interest of ruling things in and out of the equation).

[kingjafad]

Update -
So i found an amazingly handy technical document on the stop start stuff

VS Electrical Systems StARS Technical Handbook En.zip

(3.37 MiB) Downloaded 421 times

It is exactly the system in the C3.
It confirmed which pins were earth and 5V supply, also that with the plug disconnected from the alternator i am supposed to get 5V on the sensor lines. It also has info on how to test the mosfets of the ECU etc. Putting it up here for posterity should anyone else need it. To do full testing I need to take the alternator and ECU out, which is a job for another day. Also whilst I was poking and prodding, I found what could potentially be a cause.... the plastic retaining clip on the plug for the 6pin connector is broken and not holding it into the alternator with any great vigour (That could explain the suddenly not able to start and bunch of fault codes about alternator position sensor)- Ive emailed Valeo UK to see if they know where i can get a replacement plastic plug (I imagine the answer will be, buy the whole wiring loom! at a stupidly extortionate price).

Beyond that - I got the coverplate off where a real starter motor would fit, it all looks good and ready for a starter (once it arrives)

[kingjafad]

Update:
So i got a starter motor installed - and wired to a temporary trigger for the solenoid. It started fine. Happy days I thought.
Then I checked the battery voltage as it should be around 14-14.6 when charging according to the Alternator........ Damn it 11.7V Perhaps when i checked it previously it was my imagination or just a very strong battery at the time - I've been putting it through a lot of power cycles with Lexia testing etc so I sort of expected the battery to be low, but i hoped it was going to charge.
So my theory about the reversible alternator actually charging was incorrect, and now I need to get the alternator out to give it a good test. Oh well, its dark now so job for another day!

[kingjafad]

Update:
I checked the AC voltage coming from each of the phases- seemed to get only 0.7v AC on each (could be a discrepancy with my multimeter)

Managed to find time to battle rusty clips, how to compress the belt tensioner when Citroen dealers themselves even claim they dont have the correct tool, and then how to get a round peg (alternator) our of a square hole (had to undo the top of the grill/crossmember and pull it forward about 2 inches to get the alternator out) - At least i didnt follow the youtube video of a garage actually undoing engine mounts and pushing the engine back to get the room - that was just plane crazy to watch!
Anyway, in bright light and warmth indoors, I tested both ECU and Alternator - Followed the mosfet checks in diode mode as per the guide, all good (and i'd already checked that the 5V on the cable to alternator on the pins 2,3,4,5 were good whilst it was in the car). Next the alternator tests - all insulation good, 3 coils good, rotor (including bushes) good. Exciter coil (if thats what the 2 pin connector is called)- a little high in resistance (about 30ohms) but the guide didnt have a figure for that - at least its not open circuit or shorted to earth.
And then i spot it....... Pin 3 on the 6 pin connector is flattened down (not shorting to anything luckily) - Well that would probably explain why I was getting error code P1390 - Position Sensor as pin3 is the sensor for Phase 'V'. I managed to straighten it...... There may be a chance it will all work properly when i get a chance to put it all back in - I know I am expecting a lot! I am thinking that the reversible alternator/ECU combo is smart enought that it doesnt generate anything if the combination of itself and the ECU determine its broken - fingers crossed thats the reason i got next to nothing on each of the 3 phases.

As a fallback I had already resigned myself to getting a simple KFU engine scrappy Alternator to drop in and just live without stop start. (My logic was that a simple non reversible alternator has all the rectifier, regulator stuff built into it so the output could go straight to battery to charge it and not need to go via ECU (given the 12v 'sense' from wherever it would normally come from on KFU engines - I am reading that the sense can come direct from battery - but not sure on that just yet)
Again - just documenting this here for the benefit of others that may be in a similar position

[ozvtr]

Update:
I checked the AC voltage coming from each of the phases- seemed to get only 0.7v AC on each (could be a discrepancy with my multimeter)

My guess is that's just induced voltage from the residual magnetism of the rotor.
Did you check the voltage being supplied to the rotor while the engine is running? It's the same as the process "checking rotor impedance" but checking volts not ohms.
If you are getting volts there, something must come out of the 3 phases. In that case it might be a problem with the connector.
If you are not getting volts there (at the rotor) you'll never get anything out of the phases.
From an engineering stand point, if you have a failure of the phase rotation sensors there is no reason why the "alternator" function wouldn't work. But then again I didn't design it! It could be that one failure shuts the whole thing down.

The only thing that you have to go on is the ECU whinging about the phase rotation sensors. I wonder if that module is replaceable? You would expect that the carbon brushes for the slip rings would be replaceable, so is it possible that the phase detection module is replaceable?

[kingjafad]

thanks ozvtr - I have no idea why my old brain didn't pick up previously on what you have clearly just reiterated - if no (DC) voltage is getting to the rotor, ill get nothing (AC) out on the stator - I think brain fog had clouded my understanding of how a basic generator works. I had assumed this reversible alternator was some overly complicated bag of tricks, but clearly not. It didn't even dawn on me that in the pictures from that technical guide, the rotor is simply the 2 pin connector (why they show testing directly on the 2 bolts under a plastic cover that required a bit of a risk snapping said cover off......) Anyway, just to be absolutely sure, i tested resistance between the 2 pin connector and rotated the rotor and sure enough it was the same as measuring on the bolts....slight varying low resistance as it goes around the slip rings (tech guide says 0.5 to 100ohms - i got between 13 to 40 as it rotated) - No idea why its taken that penny so long to drop in my brain!
I had intended to test the voltage across those 2 wires whilst it was in the car but clearly had got side-tracked and didn't so that is definitely the next step , as you say. Due to work commitments that may not be for another week or so - but I am really grateful for your inputs/sounding board/ideas.

Incidentally, Do you have any link/suggestions on how the position sensors are likely to be operating and how to test them out of the car, given they would normally get a 5V dc feed and pin 1 on the 6 pin plug is earth (not connected the alternator body though - i checked that) - induced current that varies on the 3x 5v on the lines perhaps? Maybe similar to ABS sensors? - I have checked resistance from each of the 5 pins to each other and there is nothing showing even changing scale up to 2000Kohm.

I only found 1 youtube clip of someone changing the slip rings on this alternator but in the comments it states that the other parts are not available (like the phase sensors) .




Mine sounds like the 1st generation version in this video

[kingjafad]

Update:
I got the reversible alternator and ECU installed again - much easier going back in and hands are more or less scar free.(didnt bother with belt yet). After a few goes spinning the alternator pulley by hand and then attempting to clear the P1390 fault code, I eventually managed it - No fault codes on the Start-Stop....... Oh the joy...
But then I thought, why not try to turn the key and start it - knowing I would just get the alternator pulley moving without the belt on. But it didn't budge and brought up the P1390 and other codes suggesting alternator is blocked again. Tried to clear it as I had just done - no joy.
Now I remembered to measure the voltage for the rotor/exciter (2 pin connector) - With the plug, unplugged, it was showing 1.6V DC (supposed to be 12V would be my assumption) Now the really weird part, I turned off the ignition and I still have 1.6V DC coming from the ECU. Just to be sure it wasn't my multimeter playing up I disconnected the battery and the voltage went to 0 as expected. Does that sound like the ECU would cut it off after a while and go to sleep? (I probably should have waited with ignition off for 5 mins to see, hindsight is a wonderful thing.)
So now I am thinking - is the 1.6v DC enough to even create a hall-effect field in the position sensors? Does it need to be 12V? Should i risk putting 12V battery across the 2 pin connector? I had to disconnect the plug to measure the voltage as I didn't have any good way to back probe them but I do have some coming - Once back probed, belt installed, I can start the engine on my retro fit starter and see what is happening on the 2 pin rotor and the 3 phases at the same time. That should give me some direction.
My other thought - the 48 pin plug on the bottom of the ECU is about a foot away from the road surface, with all the salt, mud, water etc - Perhaps i have some cruddy connections - the pins in the ECU look clean visually. I think I will give it a good electrical contact cleaner squirt when i have another chance. Also the 5/6pin connector for the Position Sensors still has the broken plastic locking tag so I'll take some tie wraps/rubber band/blue peter holding firm contraption and try to make a better connection too.
The fact that I got Lexia to clear all faults..... albeit just once....... is progress though so I am treating myself to a tipple tonight.

[ozvtr]

I wouldn't risk putting 12V across the rotor. Not sure but I wouldn't risk it.

The 1.6V is probably a "probing" bias voltage. That is it's a voltage used to see if the rotor still has continuity. If the voltage went to 0V the rotor would be a short circuit. If the voltage went to (I'm guessing) 5V the windings/carbon brushes/slip rings would be open circuit. If you waited for the car to "shut down" you would probably find the voltage would disappear.
Edit: actually that statement might not be quite right. If you are just probing the the connector off the alternator, I would have expected 5V. But I'm just guessing here!

My guess is that the detectors are HALL effect, as both power and ground are applied to the connector. I believe the ring under the bearing that the guy in the video removed is magnetic. I cant see any other way that the detectors pick up the rotor's rotation speed and direction.

I don't know how the stop start ECU is probing the phase detectors. If we could find out how, we could probably confirm the ECU's diagnosis.
The only thing I could guess is checking the voltage from pin1 (or ground) of the 6 pin connector and each of the outputs of the phase detectors. I would expect a 5V square wave output with 5V applied to pins 1 and 2. If you only have a multi meter then the voltage on all 3 outputs should be the same.

[kingjafad]

Thanks Ozvtr. I did actually get another minor bit of progress today (only got chance of about 30 mins at lunch) - with the help of someone physically pushing the 6 pin connector fully home and holding it there, I can repeatedly clear the sensor fault in Lexia - So definately a problem with the plastic clip causing that - tried rubber band, tie wrap but neither had a good place to grip and hold the connector in place so I am going to have a think about a better solution (Valeo never came back to me about a replacment plug and ive not found a wiring loom going cheap yet). On top of that, my 'helper' said that (after clearing all the faults) when i turned the key to start, the pulley did make an attempt to move but then I get p1390 position sensor, alternator blocked etc fault codes - Maybe due to me not having the belt or tensioner on yet. As I said, with him holding the plug in place, I can erase the codes again fine.
Also I finally found my piercing probes that i thought i had lost so i plan to get a live reading of the rotor voltage tomorrow (and perhaps the 3 position sensor wires too.) - Something I noticed that may or may not be relevent to the rotor votage/current is that the gauge of wire to those 2 rotor pins is pretty hefty - probably akin to normal household 13A wiring if not a little thicker
As for checking the position sensor lines - I do actually have a neat little portable scope so i can try that too - I'd invested in a few new toys. (My new multimeter also has a duty voltage/Hz setting - not that i am fully confident on on where to test things with that yet) - Any progress, however small, is still the right direction

[ozvtr]

On top of that, my 'helper' said that (after clearing all the faults) when i turned the key to start, the pulley did make an attempt to move but then I get p1390 position sensor, alternator blocked etc fault codes - Maybe due to me not having the belt or tensioner on yet.

Ah! So the controller "kicks" the rotor and "looks" for output from the position sensor(s). That's why you don't get error codes until actually try to start the engine. I wondered how it knew there was a problem.
I would concentrate more on the position sensor module. Pull it out, give it a good once over.

Scope would be a better idea. As I said, my guess would be a 5V square wave from each of the detector outputs. If the scope has multi channels, you should see a 120 degree phase shift between them. My bet is you get 1 or more dead outputs (could even be the whole lot).

[kingjafad]

Thanks Ozvtr. That makes a lot of sense - if it doesnt think the rotor has moved (due to feedback from position sensors) then the test 'kick' doesnt push its luck and backs off and assumes all manner of stuck rotor problems. I didnt get a chance yet to get my scope on the sensor cables but i did manage to back probe the rotor voltage feed from ECU a little better (better meter) - With the plug disconnected i am getting 2.6V dc on the wires (dont know why my old meter only showed 1.6v) but as soon as its plugged in it goes to 0v - I double checked that neither pins on the alternator is shorted to ground. So not sure if that points to a problem with the ECU or an engineering choice whereby it thinks it should be 0V if the rotor is stuck? but then why give 2.6v disconnected? Scratching my head a bit there.
Edit: Sat 1500hrs
I did get the scope on the sensor pins and fixed the plug so it holds in firmly, cleared all faults:
Got the car started with my retro starter and took some readings.
Sensor pin3

Sensor pin 4

Sensor pin 5

I took a video too but cant seem to add it here - it doesnt show anything different from the photos though.

I also got Lexia watching the voltage supplies screen and the exciter voltage shows 0V (which is probably the smoking gun now)

I checked with the car running and stopped, exciter voltage was 0V either way. So the Stop Start ECU is clearly lulling me into false hopes with a 2.6v DC on the wires until its plugged into the alternator. Any more ideas on that front are very welcome

I will persevere a bit more but in the mean time I want to get my 'simple' scrappy alternator put in and prove that it can charge the battery - from the 'non stop start' wiring diagram Marc kindly put up at the start of this thread (page 1) I see that it uses pin2 to control the alternator output

Do you (or anyone) know if that is a simple 12V from some point furthest from the battery or is it a PWM feed from an ECU somewhere (basically i am looking to see where to attach that wire given I have a wiring loom for a Stop-Start car, not the normal layout (my engine is the 1.4 ET3J4 KFU petrol 90hp seen in a few different models -c2,c3,207 etc shows as Injection ET3J4 in sedre) - My SEDRE wiring diagrams doesn't display anything for this C3 though (rpo 11680) but it does display wiring fine for my other cars.
If i left that pin 2 off, what would be the consequences for a short test of charging (will it destroy the battery?) Is that pin 2 actually the exciter voltage (it doesn't look like it from the diagram but I'd prefer someone with more experience to confirm that please).
Cheers.

Edit:
On a 206 (same age and engine and same component for alternator according to DocBackup) the wiring is:

On that one, pin 1 is coming from the battery light indication (or so it seems as i followed it back to the ignition key switch in the diagram) - Am I being daft or does that suggest, the scrappy alternator is self exciting, and the pin 1 just controls the battery light on the dash, pin 2 can be used by the Engine ECU to control output but not entirely essential?

[ozvtr]

Edit:
On a 206 (same age and engine and same component for alternator according to DocBackup) the wiring is:

On that one, pin 1 is coming from the battery light indication (or so it seems as i followed it back to the ignition key switch in the diagram) - Am I being daft or does that suggest, the scrappy alternator is self exciting, and the pin 1 just controls the battery light on the dash, pin 2 can be used by the Engine ECU to control output but not entirely essential?

The single wire is only for a "charge fault"(alternator fail). Pin 1 is for an "old school" lamp. Pin 2 sends a fault signal to the engine ECU and the engine ECU sends out a "fault message" on the CAN BUS. The alternator on the right is the old school version, left is the new version. However I'd like to get my hands on the Valeo electrical engineer who signed off on a charge fault circuit that doesn't detect a charge fault!! Or the lazy SOAB that couldn't even put in 1 extra LED for ECO mode??!! Lets just confuse every body and have the battery light flash!! Um..sorry...rant over.

Bummer. Looks like all three rotation detectors are working. The two pulses might be because of the change in polarity of the magnetic flux. It doesn't matter, it still looks good to me.
So why is the ECU complaining about a failed detector? Did you back probe the stop-start ECU end of the loom? Inspect the connectors at the ECU end?

[kingjafad]

Update - Well, i ended up putting the scrappy alternator in and it works fine. I thought i could get rid of the start stop ECU completely (it sits low down next to the radiator behind the plastic front grill so its open to the elements). Turns out, as expected really, that the car wouldn't run without it. So i plugged the 48pin plug back in - leaving the 3 phase wires off, and the sensors 5 pin and the exciter 2 pin plugs off. I got some 100A cable to go from the alternator the 10 inches or so to the start stop ECU main battery connection. It all works fine, amp clamp shows battery charges fine at a reasonable rate, and the alternator itself is capable of feeding 70/80 Amps where needed.
If i ever get the time/inclination I will pull the old Reversible Alternator apart to see if i can see any snags with it - I did find broken magnetic fragments in and around the stators and there is a little grinding noise when spinning the rotor with a drill - I imagine the some of the magnets have broken.
To top it all off, I ran the 'remote starter' cable through to a 20A push button for the starter solenoid via a fuse which works a treat. I looked at the BSI module and on non stopstart versions it has a 5 pin chunky cable connector (yellow) where pin2 would be the solenoid feed but its not wired on mine, I may see if it still puts 12v out on pin2 but right now there isnt a rush.
Car starts fine with a button, charges battery fine, only error code is that the alternator position sensor (which it no longer has) isnt working - So i am reasonably happy with it now.

[kingjafad]

Just a quick follow up on this thread in case people wonder what happened over the last year or so. Well, it has been absolutely fine on the charging/starting front with the scrappy basic alternator and starter. Its had a run in with central reservation (not me driving.......), a suspected automatic gearbox failure (so the AA said) which turned out to simply be needing a new clutch (btw the gearbox is much heavier and a pain than clutch replacement youtube videos would have you believe...... I ended up using a hoist to hold the gearbox from above to refit).
But as far as the original thread is concerned, the car works fine.