[epsonix]

CAN is fone since other CAN transmitted commands work(vol/on/off). No relays on the way. Last check is power/ground on purple connector, if good checks are more work (other side of cable and temporary swap of display or etm for quick check)

 

[tazztham]

alright...i guess need a weekend to chk ETM voltage and wire to display. can thing of anything else. Some owner experience same situation like my but the problem "fixed" by itself after awhile. Some said battery is relatively weak and the ECU/ETM shut the display out which i doubt has that feature. After battery changed, all ok back....italian electronics... 😢

 

[tibimakai]

Try to use a flashlight on the screen, see if there is a faint display visible. I'm thinking, that maybe the backlight could be out.

 

[epsonix]

alright...i guess need a weekend to chk ETM voltage and wire to display. can thing of anything else. Some owner experience same situation like my but the problem "fixed" by itself after awhile. Some said battery is relatively weak and the ECU/ETM shut the display out which i doubt has that feature. After battery changed, all ok back....italian electronics... 😢

check battery even with voltmeter, no cost, 10s job. there were some gremlins with weak batteries, but mainly it was in 2016/17 cars with old ICP firmware, where display in the centre of ICP was black in such situations - after charging usually it was back. Newer firmwares for ICP resolved this problem. With weak battery you rather may have like false error messages in engine etc due to too long starter load/too deep glitch on voltage and so sensors readings spoiled. I never heard about ETM display not to fire up.

Electronics is not Italian - Displays are made in France by Magneti Mareli, ETMs also MM, but as far as I know it was the same subcontracting company in germany who did bit earlier BMW infortainment to be reponsible for Giorgio infotainment design. Of course as all on the world so complicated, may suffer bugs and may suffer assembling or components fails/out of specs etc.

If you were located somewhere nearby me or a few colleagues of mine around Poland (specialists Alfa garages or retrofitters), there would be no problem to quickly get hardware to check - easiest any ETM out of the shelf (for MY20 displays it is required 3rd get ETM MY20 as older do not support new displays - black)- just to see if displays fires up. E.g. I have still one MY20 ETM brand new nav/camera/aa/acp unit and one 2nd hand/spare (working but after water ingress so only as spare - not for resale). Displays also I have some (e.g. bit cracked MY20 stelvio). It was time when I was doing retrofits that I had 25 ETMs on my shelf, half new (2nd and 3rd gen). Maybe you will look for garage who has such? Or good guy from forum who will let you borrow for sec his own ETM out of any MY20 GIulia/Stelvio? Then also fit your ETM to other car. At least you would narrow well confirming if matter is on your ETM (not working in other car) or your cabling/display (if other ETM won't display in your car). No need to connect anything else than main socket and display.
Getting to display is bit of disassebling job (panel in passenger footwell,glovebox to gain access to 3 bolts, passenger vent, dashboard decor panel, ICP) - so this you may leave for separate time if turnes needed (confirmed fault between display and cable)

 

[tazztham]

Try to use a flashlight on the screen, see if there is a faint display visible. I'm thinking, that maybe the backlight could be out.

i did that and seem like it is pitch dark nothing...no blacklit at all. i tried it under a very dark condition. so something else.

 

[tazztham]

check battery even with voltmeter, no cost, 10s job. there were some gremlins with weak batteries, but mainly it was in 2016/17 cars with old ICP firmware, where display in the centre of ICP was black in such situations - after charging usually it was back. Newer firmwares for ICP resolved this problem. With weak battery you rather may have like false error messages in engine etc due to too long starter load/too deep glitch on voltage and so sensors readings spoiled. I never heard about ETM display not to fire up.

Electronics is not Italian - Displays are made in France by Magneti Mareli, ETMs also MM, but as far as I know it was the same subcontracting company in germany who did bit earlier BMW infortainment to be reponsible for Giorgio infotainment design. Of course as all on the world so complicated, may suffer bugs and may suffer assembling or components fails/out of specs etc.

If you were located somewhere nearby me or a few colleagues of mine around Poland (specialists Alfa garages or retrofitters), there would be no problem to quickly get hardware to check - easiest any ETM out of the shelf (for MY20 displays it is required 3rd get ETM MY20 as older do not support new displays - black)- just to see if displays fires up. E.g. I have still one MY20 ETM brand new nav/camera/aa/acp unit and one 2nd hand/spare (working but after water ingress so only as spare - not for resale). Displays also I have some (e.g. bit cracked MY20 stelvio). It was time when I was doing retrofits that I had 25 ETMs on my shelf, half new (2nd and 3rd gen). Maybe you will look for garage who has such? Or good guy from forum who will let you borrow for sec his own ETM out of any MY20 GIulia/Stelvio? Then also fit your ETM to other car. At least you would narrow well confirming if matter is on your ETM (not working in other car) or your cabling/display (if other ETM won't display in your car). No need to connect anything else than main socket and display.
Getting to display is bit of disassebling job (panel in passenger footwell,glovebox to gain access to 3 bolts, passenger vent, dashboard decor panel, ICP) - so this you may leave for separate time if turnes needed (confirmed fault between display and cable)

really appreciate your help and guidance. today, i managed to remove the radio/ETM and measure the purple socket (for display) 2 wire beside it. Indeed yellow power/B+ and Blue groud as shown in diagram above. however, the voltage was only abt 6-8V (unstable) measured directly from the ETM purple terminal. when i plug in the display cable and measure again, it is 0V and seems like not enough amp to power up the display. I wonder it is a slim change the BCM so smart it didn't send the display on signal in the CANBUS to turn on the display due to "Battery Weak" which i doubt so as i got about 12.1V on battery terminal. BTW, I also measure the CAN IHS Low and HI with right voltage 2.4V & 2.7V. I think wiring shld be ok.

I wonder can i just supply 12V directly to the display without damaging it just to check wire and display condition? This is my unit and I am not sure which ETM with different HW/SW is compatible with my MY22 Stelvio. Anyone has one close to this part nbr, i am willing to pay for the shipping and try out. If it is a faulty ETM, i will pay for your unit.

Thank you very much in advance.

 

[epsonix]

Yes, your CAN is right, I can't guide you on supply for display unfortunatelly, what you have though seems wrong. Did you open your ETM to see inside if no obvious failures/corrosion due to say water or just burnt component/track? Can you go through from power supply input to display power output to see if this paths seems at least kind of looking good, tracks pass etc? Maybe ideas for fix will come without having schematics (if the circuits is some simple - I have no clue). With ETM out, check with ohmmeter if there is direct pass from ground of ETM power input to pin on display connector.

In terms of ETM, if you find your unrepairable, I said I have one brand new. High China - I'm pretty sure the only difference with yours is that your had Japan maps preloaded and mine has China's. I retrofitted 6 of such into EU/US cars for polish market, maps loaded later OK, activated AA/ACP (I could preactivate before shipping/before ETM will lock for VIN of my car). The only problem with Malasya (at least this flag displays at your posts; I though for last week displayed with Italy, just before my IP was holiday place, where Im located in Poland) is that customs come to game, so aside of international shippments, all sorts for customs fees add on top (no matter I got ETMs pile of ETMs on some stage from excessive stock clearance/sale from Stellantis, so can offer in good price that last one). Priv me if you get to point you need new ETM.

 

[tazztham]

i managed to disasemble the ETM and have a look, circuit is complex and the main terminal of the back of the ETM has 2 x multipins tiny connectors to the main board. So very hard trace and it won't be a direct connection anyway to the display power output as it is under a switch circuit. honestly the ETM circuit is very fragile. even the input from battery is with thick pin, but when come to internal connection, it is so so tiny and smaller than a 15A fuse wire. the PCB seems normal and no sign of damage.

so for the display panel, does it has any indication at the back/lable saying the input is 12V? i wanted to feed a 12V directly and see if the display has any display. I guess nothing wrong with it probably as the ETM power output only 6-8V as i mentioned.

will PM you for the ETM and details how to install a new ETM. Thks.

 

[epsonix]

I do not know for sure but schematics you pasted with pin names suggest it is just reforwarded fused battery from ETM input, so should be good (hopefully). Hower there is no direct pass on this line, as far as I quickly measured with ohmmeter on some old unit I have in house, I seen like 250kOhm between these. I guess ETM has some transistor or so to enable or disable power to the display. On ground there is expected direct pass, so first check ground pass with Ohmmeter like I did below:

On new ETM installation, main challenge is activation of android auto/carplay,as new units come with this not activated, and only some more expensive OBD tools support the function (Witech2 dealers use, Autel where annual subscribtion is USD350, but if you buy my unit, I can preactivate AA/ACP connecting to my own car, do proxi, do activation, remove back to my ETM do proxi - so some 1h like job in car but can do this and used the method on 2 units I shipped where people had no own solution fo ractivation of aa/acp, only for proxi). Rest is just easy installation and proxi run. Anyway, before you go into costs of new ETM, you need to be sure it is the ETM to replace (maybe since the power to display looks like does not go through at any load; did you tested this with unit connected to the car and radio working or just connected to the car but radio not working to make sure display should be enabled/powered?).
Generics of installation we can discuss here, only the buy/ship part if you decide to buy from me, we will discuss priv.

 

[tazztham]

Yup, it is not a direct forward of 12V from the ETM main socket pin A15 to the display socket. It has an internal switch with CAN signal. For old day head unit, it will use a "ignition" 12 supply to fully activate screen/display. But this all controlled by CAN bus signal and that is why i am still finding way how to be sure to know there is a signal to turn on display. The Ground pin is ok no problem. Today i did another round of voltage testing after dismantle the ETM unit yesterday hoping it get fixed. Unfortunately not. So with the radio on music playing, i recheck again the power output with the purple connector connected. Only reading 2.5V which is either is not turn on or the internal switch not working. Next i am thinking to do some risky test. With the 2 power supply wire remove from the purple socket, i want to supply 12v directly to it and see if any display. if so, meaning really ETM got some issue which is bad luck. Do you think it is save to do so? The display panel can take 12V right?

on the side note, i realize the Stop/Start is not triggering for some reason. Meaning either the battery SOC & SOH is not within range to do so. What do you think?

BTW, is there suppose a fuse at the back of the ETM main socket? Thks.

 

[epsonix]

I already commented in last post on connecting 12V directly to purple connector. We have only indication from your schematics that this should be battery 12V fused, just over some kind of switch/transistor whatever. We have no other solid confirmation that it is really 12V (in case designers changed mind and service diagrams were not updated or done just so so). With only pin name you probably have only some limitted confidence it is really 12V and nothing bad will happen to display. But if you do not have any other unit to try now, that is reasonable to check (with only minimal risk?).
I guess fuse they mean on fusebox, unless there is some other internal like THT/SMD fuse inside ETM? I have no clue, I have no schematics of internals and never looked any deeper (had some opened by curiosity only, as well as in one which turned faulty, I replaced back supply part (one with power socket) out of other unit (here reused 1st gen donor which I didn't need to repair 2nd gen ETM).

S&S is not working in many conditions, though most common (if there is no any ECM errors or extreme conditions like super low temperature), that SoC reported by IBS is below 65%, what agian is very common both due to specific charging strategy, often issues with quality of IBS sensors (aging/misbehaving/stupid readings), and also batteries in poor condition (quality or aged due to both other things I mentioned). SS nothing to do with display not working.

 

[tazztham]

alright... i guess i can't just simply supply a 12V to the display directly as i have no extra part ard. Anyway i dont think is the display issue as my ETM purple terminal has no 12V output. Will need to go with different option such as getting parts first to try out....sad 😢 why the ETM failed for a relatively new car.

 

[epsonix]

I do not know if you can't try, you can, with some probably minimal risk. If I was you, I would also hesitate, but maybe especially leaving in Malaysia and not having around any other ETMs to try, I would risk, cut power wire in purple connector, and connect there some other - maybe though not too big fuse like say 2-5A? Really it is not common to have either MY20 ETM (nor even MY18; opposite is MY16-17) failing or displays failing (once ever I saw display with some section of it not working at all, but all rest was working fine; of course on displays we have cracking issue of the anti-reflective layers, but that is cosmetical issue, I refer to like completely dying display - never came across such). Just bad luck I guess.

 

[epsonix]

I did test you said no chances to work and looks like you were wrong with assuming supply won't go to display pins without CAN commands to wake up.
I took random 2nd hand 2019 LOW NAFTA unit, just plugged power 12.8V and on purple connector I seen ~12.4V every a few seconds interrupted for some short time (hard to say 50-500ms? DMM reaction won't let to say and there was no point to waste time and see with oscilloscope) - possibly ETM was trying to communicate with display, failed so tried to power cycle display?)

 

[tazztham]

I did test you said no chances to work and looks like you were wrong with assuming supply won't go to display pins without CAN commands to wake up.
I took random 2nd hand 2019 LOW NAFTA unit, just plugged power 12.8V and on purple connector I seen ~12.4V every a few seconds interrupted for some short time (hard to say 50-500ms? DMM reaction won't let to say and there was no point to waste time and see with oscilloscope) - possibly ETM was trying to communicate with display, failed so tried to power cycle display?)
View attachment 36919

Oh yeah, with the power supply at Pin A12 & A15, you get some power output fr the purple pins but cycling on/off? so you have a spare display that could plug in and see? It will be interesting to see.

 

[epsonix]

yes, that is what I got. with at least MY19 ETM I had at hand in office. I have displays, but I do not have cable to connect to display. What I can do for you only right now, is to connect power using standard femeale-female prototype board cables and 1. see if backlight comes up, 2.how voltage looks under load conditions.
I have some CAN analyzers/recorders/software/interfaces but all still in boxes/not installed/no cablings made etc (all for projects I have on my roadmap) - so on some stage I could do some recording in my car of CAN messages and then cycle all on the desk so get radio power up on desk fully, with screen on (I would need to get also ETM to display cable from somewhere). But no time now to look at this - as we talked private I was able to give you more support during time I was away abroad recently, but now back in dealing with business daily and whole pile of matters and priorities which never ends and new pop out every now and again.

 

[tazztham]

yes, that is what I got. with at least MY19 ETM I had at hand in office. I have displays, but I do not have cable to connect to display. What I can do for you only right now, is to connect power using standard femeale-female prototype board cables and 1. see if backlight comes up, 2.how voltage looks under load conditions.
I have some CAN analyzers/recorders/software/interfaces but all still in boxes/not installed/no cablings made etc (all for projects I have on my roadmap) - so on some stage I could do some recording in my car of CAN messages and then cycle all on the desk so get radio power up on desk fully, with screen on (I would need to get also ETM to display cable from somewhere). But no time now to look at this - as we talked private I was able to give you more support during time I was away abroad recently, but now back in dealing with business daily and whole pile of matters and priorities which never ends and new pop out every now and again.

i dont know if my cheapo multimeter is not able to response to the time or not bcos only can read about 8V during no load with power connected to ETM. anyway I will do more test and see how. so far couple of owners in the forum claim it is the battery "weak" not enough 12.5V or so and the BCM just decided not to turn the screen on. I am going to test out a new battery in 1-2 days and see how and I really really hope that is the cause. Otherwise, i am in deep trouble...and burn pocket.

 

[epsonix]

12.5V battery is quite good charge. as long as it does not drop with ignitinon on very down (e.g.very poor real state no matter of seems charged when unloaded), then no reasons to take into account such.

FYI, I took MY20 unit on my desk, plugged power between display and ETM purple connectors, seen like 0.25V going slowly down. Later I seen only 0V, but I found some signal cable between ETM and display, plugged this, and once I managed to see 12.2V across display power (I have 12.8V on input of ETM). But only once, then it disappered and no matters of power ups/disconnecting cable, even brough some cracked MY20 stelvio display for change, it never re-appeared. So, guessing there is some logic, possibly this unit was freshly taken out of car where it worked, and maybe still allowed display power up attempts, but now without CAN got to deep sleep or so and does not try display? WIth current possibilites and lack of time, I can't do more testing on this. In a few months time I start work on CAN device, then I could expriment with this, when I have all setup/running, all sniffers/simulators/software/cabling/have records from car - then quite easily could try to simulate car on desk and so run ETM fully on desk with display.

 

[tazztham]

to me, it is a very good and important test you did for me. it seems like my assumption is correct that it needs a CAN signal to turn on the screen. so i guess you won't see the display lid up or has backlight because the voltage drops after that. i cant say enough thanks for doing all that to find out. cheers.

 

[epsonix]

Yes and no, in one case I got 12.2V with MY20 unit without CAN - not sure if that was time I looked well at screen to see backlight - this may come separatelly. Also, with 2nd gen unit I tested yesterday, without any load/display I seen 12.34V with every a few seconds glitches down (DMM voltage was jumping down and up hard to say what voltage), and during that test I had th. Looks like there is some sequential logic anyway which we do not understand nearly at all (possibly partially related to CAN presence, but possibly related to talks with display itself; may be test phase, may be some retries time, may be later give up phase etc), so hard to assume anything just based on simple measurement - can be either good or bad ETM or cable or display in your case.