Selected gears not appearing on display

Ozvtr wrote: ↑Sun Jan 02, 2022 12:53 am Please don't answer any questions here, I think that's the end of this thread. Put them back in your original post (if you need to).

I think this is more of an auto box problem and I think it's related to your auto display problem too.

Of course if anyone wants to ask questions about the BSI, rear wiper and reversing light circuit, then please go ahead.

sorry... read this too late...
yes...everything i think is related to the display issue

but knowing how the circuit might be (diagrams etc) and where switches etc are,
would be helpful with the investigation ...

I'm making some big assumptions here and might have jumped the gun.
The big assumption is that you are running an AL4 gearbox...are you?
If it's not an AL4 my knowledge is going to be limited.
Ok, if it is an AL4 then here is a circuit diagram. I really need to get off my a$$ and get SEDRE installed, the circuit diagrams I have at the moment are cr@p. If you provide your VIN and ask Arfur very nicely, he might provide the correct diagram. The selector switch is labeled 1635 right down the bottom. The reverse switch is the set of contacts 3rd in from the left (of course labeled R).
This diagram is for an earlier model but I believe the over all "how-it-works" is still basically the same, at least as far as the AL4 is concerned.
The fact that the reversing "stuff" isn't working is pretty straight forward however I am a bit lost as to how the display is not working.
Do the "sport" and "snow" buttons on the selector quadrant work? Sport just causes the engine to rev out more before the auto changes gears. Snow just locks it in 2nd gear. They are labeled 1640 on the diagram. You will note that they are connected to the BSI and not the gearbox ECU. If they work it means the BSI is "talking" to the gearbox ECU.

Thanks mate...really appreciated

(where can i find this SEDRE??)

not sure about the gearbox type.... how can i confirm if it's an AL4? (Very new to the Citroen world and still trying to get my head on it on codes etc )

Sport/Snow buttons both works... (keeps revs high / can hear it engages 2nd gear from stationary) ...simply not displayed...

My assumption for the display is some sort of misconfiguration between manual and auto mode...which I'll have to double check once i get lexia...
If that is a possible, scenario maybe a simple misconfiguration is the cause of all this

Tried to remove battery etc to have a better look around the gearbox area and starting to have a grasp on how everything is fitted and where...

found this switch (gear position??)...
2 pins exopsed... can't see any unplugged plug around ...

isn't it supposed to have a cable connected to the 2 pins ???

Ok...those 2 pins seems to be normal from what i can see online comparing pictures of the module... can anyone confirm that by any chance?

Also... where i the reverse switch on the gearbox? tried to follow the loom etc... but i don't seem to be able find it

Done more reading on the AL4 documentation etc...

from what i can read... the multi-function switch seems like it might be the problem causing gears to not appear on display AND reverse light not working...

guess i just really need to wait for my lexia to arrive to confirm that (or not)

Yes that's the selector switch.

The 2 exposed contacts are used to set up the neutral position. The contacts are shorted at the neutral position.

There are two bolts holding the switch in position. You could try loosening the bolts and moving the switch around (you have nothing to loose). My guess is a total failure of the switch as the indicator blinks if it is simply out of alignment.

The gearbox ECU does not use the selector switch in "manual" mode, so I don't understand why it won't display a gear. Oh well, I didn't design it, so if they say the gear indication disappears...then I guess it disappears!?
The switch wiring runs under all that metal work to the back of the gearbox to a point approximately where I have drawn the arrow. Its terminated in a big connector, made up of smaller connectors. For example the smaller plugs are for the pressure sensors, the electro valves on the valve body, the position switch and so on.

As I said, you could attempt to pull the switch apart and clean it. Again, nothing to loose.

This video is not in English but you get the picture.
https://www.youtube.com/watch?v=68iTVpugHX0

Thanks mate... appreciate your help

I did find a few videos as well on Peugeots rather than Citroens (pretty hard to find info on Citroens ehy ahahah)

Unsure as well on why it'd cut out the display if the switch isn't in good working order...

I did see the big gray connector box at the back where all sockets plug into... but... I was a bit puzzled on how to get the multi-function loom out though as it goes underneath a few mounting brackets for the gearbox and i don't see how i could be able to sneak the plug through there without loosing them up and drop the gearbox at least a little.... I'll have a better look maybe over the weekend...

I did find these instructions on how to adjust the switch...I'll give it a go before trying to pull the switch itself apart

http://www.peugeot206cc.co.uk/repair-20 ... cg79k3.htm

But i think I'll wait for lexia to arrive first to see if errors are stored...just in case 'cos those pdfs says that in theory if it's malfunctioning in anyway... you should get at least warnings on the dash (which i don't get any)

Out of curiosity, would you know how those 2 pins for the alignment work? how does it sense that it's in the right position? simply due being in the right position/angle for the selector inside the switch to touch the right connections while in N (closed circuit?)
Is it grounded by any chance to the gearbox case due surface contact or it does get a clean ground from the loom?

Ok...done some poking on that multi-function switch....

getting to free the cable ties under that bracket i was talking about was a pain...but made it at the end...

i removed it and opened it... and it seemed fine...no corrosion on contacts etc...
put it back on... aligned it with multimeter 9n those 2 pins (slightly different positions that it originally was).

Car starts only in P and N as supposed to, but same as before... no indicators displayed nor reverse light on...

Guess the switch might not be it then and I'll simply have to wait for the cable to arrive and see what i can find then (if anything)

question... is the backlight on the stick surrounding supposed to highlight the selected position OR it just simply a backlight cos the feedback should be on the display?

tommy_xx84 wrote: ↑Wed Jan 05, 2022 7:02 am
Car starts only in P and N as supposed to, but same as before... no indicators displayed nor reverse light on...

Guess the switch might not be it then and I'll simply have to wait for the cable to arrive and see what i can find then (if anything)

The reverse light switch is a VERY simple circuit. No multiplexing, ECU's or jiggery-pokery. This tells me that the fault is very simple too. The ECU's are very cunning buggers. They can tell short circuits and open circuits and tell when contacts should make and when they should break (by using the opening and closing of the other contacts). HOWEVER they only log the fault in the background and you may need a LEXIA to read them. Apparently those indicator LED's are SOOO expensive, that the engineers decided to do the owner a favor and only tell them when some stuff goes wrong. After all ignorance is bliss! And if they do tell you something has gone wrong...the indication is so cryptic as to make it next to useless!!! Sorry, rant over.
I still wouldn't discount a failure of the selector switch just yet.
Did you check the resistance of the 'reverse' contacts in the selector switch?

tommy_xx84 wrote: ↑Wed Jan 05, 2022 7:02 am question... is the backlight on the stick surrounding supposed to highlight the selected position OR it just simply a backlight cos the feedback should be on the display?

Yes. The PRNDM S and * just light up. They don't indicate anything.