[eLod]

hello,

my old battery went dead (and a new one as well), so i started measuring current, and stopped + key off, it drains 150-200mA (identified the problem last weekend, it was draining 140-150mA then, dig deeper this weekend, now it drains 190-200mA) [usually the car stands for almost a week, which is enough to drain it fully].

i have found some wiring diagrams for 2010 1.6 models and could trace the current to junction box IP/C connector pin 12 (instrument cluster + data link). getting the instrument cluster out its left side was warm to touch. the cluster has 3 connectors (24p, 16p, 20p), when disconnecting all (or just the 24p, i guess this is where powers are coming in) there is no drain. if only disconnecting the 16p one, after initial 200-250mA draw, it goes under 10mA after a couple seconds (maybe 10-20). if only disconnecting 20p the initial spike is there, but it never goes under 190-200mA, and the left side of the cluster is getting warm. made some pictures, there are some noticable brownish patterns around that side of the green circuit board is, but no explicit burn marks. i haven't got the time yet to check pin by pin on the 16p one.

my problem is, it seems the cluster panels are slightly different for different engines, for example my 16p and 20p connectors seems to have different pins then in my schematics (picture attached, it seems some pins are simply not used in mine).

so my questions

1, can somebody provide me wiring diagrams for my specific car/engine please

2, given the symptoms, is it possible something is faulty outside the instrument cluster, like some signal coming in that should be shut off, but not happening? and how to debug this easy (i don't want to buy a replace part until i am sure the problem is with the ic)

3, it seems there are many variants of the instrument cluster, trying to search on ebay and etc. my cluster has the part number c76 fez 94033-2r500 11001-769601U written on it, what 94033 (or even 94003) variants are good for me, or where can i get more info about these.

thank you very much

[The Gonz]

Interesting problem, @eLod .
Many may not notice such a drain if they're driving every day but, if left standing for a week at a time, these currents may become critical.
I can't help much with variants but someone with more technical information might reply soon.

I wonder what is kept alive after ignition is off. The only things that come to mind for this age of car are:
- clock and radio station memory, and
- security system.

If you have done the hard work of isolating the current drain to the instrument cluster, it points to the cluster illumination before the key is used, such as opening the door, displaying the odometer, car plan view and open door symbol.

The scorching around the voltage regulator marked (I think AD807) is probably normal for the age of car, since the regulator's job is to take the 12-14V down to whatever some components need for the board. The difference is dissipated in heat. Is there any other identifying data for the regulator? What are the voltage readings on each of its pins I,G and O? If IGO is In-Ground-Out, you should have 12-14V on I, 0V on G and something in-between, maybe 5V, on O.

[eLod]

thanks for the info @The Gonz

yes, i know, if i would be using the car daily i wouldn't have noticed the problem

i tried my best, clamped all the door sensors, manually switched tail gate's lock, and etc., even locked the alarm. all the indicators and everything works as expected.  the instrument cluster (and everything else) works as expected, only illuminates when "needed" (on door opens), no display on radio, no lights on BCM. so when it drains the 200mA nothing is illuminated or showing the cluster is "in use" by anything.

it's not strictly ignition, if i lock everything, open up the covers around the instrument cluster, and only by connecting/disconnecting the IC connectors, i can jump between the 200mA vs 10mA drain, without doing anything else. also when found the problem, i have already disconnected all the connectors from the IP junction box (only IP/C for the cluster and IP/H for power, then even disconnecting IP/C and only connecting its pin 12) and the drain was still present.

i am not sure, but i think the main source of the heat is not the AD807, in terms of when connected and trying to move my finger around the board the highest temperature seems to be lower (maybe around those double R59 R68 labeled stuff, see photo), but i cant tell for sure, bc i did not connect the board facing me (not sure if i can, the wires are very short), so i could only reach behind it without visual confirmation.

can you please help me, explaining some of your questions, i am not knowledgeable enough (i am an engineer, but developing sw, so i am not afraid of wiring diagrams, but it's certainly not my strong suit). what do you mean by "any other identifying data for the regulator", labels on the circuit board itself? in my wiring diagram (for the 1.6 engine)? or on the internet?

just to be sure, how do you want me to measure the IOG voltage, I compared to G or I compared to car's ground? (again sorry for silly questions)

unfortunately i can't debug on the streets here at my flat, bc i don't have enough space and peace, only on the weekends when i visit parents in countryside, until then i try to collect as much info as i can.

[The Gonz]

thanks for the info @The Gonz

yes, i know, if i would be using the car daily i wouldn't have noticed the problem

i tried my best, clamped all the door sensors, manually switched tail gate's lock, and etc., even locked the alarm. all the indicators and everything works as expected.  the instrument cluster (and everything else) works as expected, only illuminates when "needed" (on door opens), no display on radio, no lights on BCM. so when it drains the 200mA nothing is illuminated or showing the cluster is "in use" by anything.

it's not strictly ignition, if i lock everything, open up the covers around the instrument cluster, and only by connecting/disconnecting the IC connectors, i can jump between the 200mA vs 10mA drain, without doing anything else. also when found the problem, i have already disconnected all the connectors from the IP junction box (only IP/C for the cluster and IP/H for power, then even disconnecting IP/C and only connecting its pin 12) and the drain was still present.

i am not sure, but i think the main source of the heat is not the AD807, in terms of when connected and trying to move my finger around the board the highest temperature seems to be lower (maybe around those double R59 R68 labeled stuff, see photo), but i cant tell for sure, bc i did not connect the board facing me (not sure if i can, the wires are very short), so i could only reach behind it without visual confirmation.

R59 and R68 are surface mount resistors.
R=resisitor
C=capacitor
D=diode
TR=transistor
IC=integrated circuit

can you please help me, explaining some of your questions, i am not knowledgeable enough (i am an engineer, but developing sw, so i am not afraid of wiring diagrams, but it's certainly not my strong suit). what do you mean by "any other identifying data for the regulator", labels on the circuit board itself? in my wiring diagram (for the 1.6 engine)? or on the internet?

Just what else is on the regulator. I'm not confident 'AD807' is enough to identify it.

just to be sure, how do you want me to measure the IOG voltage, I compared to G or I compared to car's ground? (again sorry for silly questions)

Meter on volts range to cover up to 14 or so volts, negative lead on car ground (metal frame, screw hole, etc.), positive lead as probe for each of the I, G and O legs of the device. Careful not to touch more than one at a time!

[eLod]

can you please help me, explaining some of your questions, i am not knowledgeable enough (i am an engineer, but developing sw, so i am not afraid of wiring diagrams, but it's certainly not my strong suit). what do you mean by "any other identifying data for the regulator", labels on the circuit board itself? in my wiring diagram (for the 1.6 engine)? or on the internet?

Just what else is on the regulator. I'm not confident 'AD807' is enough to identify it.

well i'm not even sure if its AD007 or AD807, i only have the pictures taken and they are not enough good quality to zoom in and see all the writing. as i said unfortunately i don't have the option to disassemble the instrument cluster here around my flat.

just to be sure, how do you want me to measure the IOG voltage, I compared to G or I compared to car's ground? (again sorry for silly questions)

Meter on volts range to cover up to 14 or so volts, negative lead on car ground (metal frame, screw hole, etc.), positive lead as probe for each of the I, G and O legs of the device. Careful not to touch more than one at a time!

thanks for the detailed info, appreciate it. maybe i'll take a day off, try measuring and take better pictures. i want to gather all the info i can before testing it again to minimize loops.

[The Gonz]

Here we go. Don't ask me to recount how I found it: a lot of guessing and random searching of manufacturers' logos.
TLE4294G V50 - Infineon Technologies

We now know (I guessed it) it regulates 5V on the O pin and delivers up to 30mA before shutting down. It's basically an equivalent to an LM7805 or 317. If you're not getting very close to 5V out of the O pin, you have a problem. If you are, you can discount a lot of the rest of the board. Either way, a circuit schematic for the instrument cluster would be great now.

[eLod]

thanks, i have also found the 5V in the schematics, so i would already guessed on that, sry if was not clear/explicit.

as i said i only have the wiring diagrams for the 1.6 variants found on the internet, let me attach the 4 pages for the indicators & gauges. as i said the connector shapes/pins/locations are similar, but it seems not all the pins are used/not the same exact pin layout with my engine.

[eLod]

actually i got some time to debug further, here are some info

the regulator has the following text on it: AD007 4274GV50

measured the IOG as you instructed, I is 11.85V, G is 0V, O is 5.02V so i guess this is alright.

the circuit boards still is warm, and it's the most warm at the spot i marked earlier (there, and left to it, so around R75 R76 and the other stuff)

i tried my best to isolate pins on the 16p and 24p connectors (the 20p one i keep disconnected as it does not seem to affect the drain), but i don't have enough small wiring to connect all the pins and disconnect only some.

for my 16p connector, actually there is only 8 pins actually connected, 3 from top row, 5 from bottom row. the 3 at top does not seem to affect the drain. when look at the female socket from front the pins are 9 10 11 12 13 14 15 16, from those only 10, 11, 12, 13, 14 are connected. if  connect only 10, 13 and 14 after the initial load there is no drain (measured, after around 1 minute, it goes from 180-200mA to 10mA (i can't measure more precisely/on smaller scale bc it will blow my 200mA fuse)). if i connect 10, 11 and 12 (or 11, 12 and 13) the 180-200mA never drops.

i also noticed all the pins on the bottom row are 12V (around 11.8V) (and none from the top row) compared to car ground, and when connecting them directly to car ground the lcd panel illuminates/turns on.

i also measured, but there is no current going through those pins, so i suspect it's going through the 24p connector. i tried to only connect some pins from the 24p connector, but i only have 3 reliable small wire connection. i connected pins 13 (room lp power) 15 (cluster power) and 23 (ground), this way the draw was only 100mA going through the ground (23) wire.

[eLod]

oh i also wanted to mention something strange. so the drain problems started multiple weeks ago, i bought a new battery and when i noticed it drains that too i started the investigation deeper. i have a blue drive (ISG), but since i bought the car (about 2 years), ISG never worked, and the ISG OFF light was on, no matter if you pushed the button. neither the previous nor the current battery is a start stop battery, so it's normal ISG was not working, however when stalled and the clutch pushed it started up automatically (without key turn). now last friday (so well after the draining problems started) i went for a short drive and the ISG system started working, i noticed when it stopped the engine at a red light, the "auto-stop" indicator was lit on the instrument cluster, and i could switch on and off ISG with the button.

[The Gonz]

One observation at a time:

- interesting point for your awareness: when your row of pins showing 12V are connected to ground (not something you would normally do without risking a short) and the board lights up, this is showing that those pins are meant to be grounded when connected, and that by grounding them you have completed the circuit and made the board function. We call this a floating earth because through lack of connection you have allowed the whole board to float to 12V.

The biggest point to take away from this is that you should leave those bottom pins connected when checking voltages around the board. Otherwise you'll be chasing false voltages.

[The Gonz]

Next observation: the instantaneous high current that settles to a lower level is likely the various capacitors on the board (the components marked Cxx). These may be small surface mount devices (SMD) looking like the resistors and diodes or they can be larger metal can types. Capacitors used to be called accumulators because that's how they work - two plates spaced evently apart that allow current to flow but soon build opposing charges across the plate gap and stop the flow, creating a damping, filtering, storage effect. The time it takes for the capacitor to reach full charge (like a short-life battery) is called its time constant and measured in a few seconds at most.

[eLod]

One observation at a time:
- interesting point for your awareness: when your row of pins showing 12V are connected to ground (not something you would normally do without risking a short) and the board lights up, this is showing that those pins are meant to be grounded when connected, and that by grounding them you have completed the circuit and made the board function. We call this a floating earth because through lack of connection you have allowed the whole board to float to 12V.

sorry for my ignorance, but does that mean i could possibly have damaged the cluster?

[The Gonz]

You mentioned blowing a fuse when using your multimeter to measure current. Be careful that as an ammeter it is used in series with the circuit, not parallel to it as when you use it as a voltmeter.

[eLod]

You mentioned blowing a fuse when using your multimeter to measure current. Be careful that as an ammeter it is used in series with the circuit, not parallel to it as when you use it as a voltmeter.

so you said "for your awareness ... (not something you would normally do without risking a short)" which i interpreted as a polite way of "don't do this ever or you damage your board", and asked if there is a possibility i already did (by connecting those pins to ground).

i know i have to measure ampers in series (and volts in parallel), what i was referring to is that i know for experience i can fry the 200mA fuse (i have replacements though), so i don't want to try and measure it in a smaller scale bc i am afraid i will blow the fuse (bc when i connect/disconnect the stuff around the initial load goes slightly above 200mA). on the 10A circuit i only see 0.20 - 0.19 - 0.18 (or 0.01 if the drain goes away), but i can't measure it more precisely.

[eLod]

the regulator has the following text on it: AD007 4274GV50

measured the IOG as you instructed, I is 11.85V, G is 0V, O is 5.02V so i guess this is alright.

the circuit boards still is warm, and it's the most warm at the spot i marked earlier (there, and left to it, so around R75 R76 and the other stuff)

i tried my best to isolate pins on the 16p and 24p connectors (the 20p one i keep disconnected as it does not seem to affect the drain), but i don't have enough small wiring to connect all the pins and disconnect only some.

for my 16p connector, actually there is only 8 pins actually connected, 3 from top row, 5 from bottom row. the 3 at top does not seem to affect the drain. when look at the female socket from front the pins are 9 10 11 12 13 14 15 16, from those only 10, 11, 12, 13, 14 are connected. if  connect only 10, 13 and 14 after the initial load there is no drain (measured, after around 1 minute, it goes from 180-200mA to 10mA (i can't measure more precisely/on smaller scale bc it will blow my 200mA fuse)). if i connect 10, 11 and 12 (or 11, 12 and 13) the 180-200mA never drops.

i also noticed all the pins on the bottom row are 12V (around 11.8V) (and none from the top row) compared to car ground, and when connecting them directly to car ground the lcd panel illuminates/turns on.

i also measured, but there is no current going through those pins, so i suspect it's going through the 24p connector. i tried to only connect some pins from the 24p connector, but i only have 3 reliable small wire connection. i connected pins 13 (room lp power) 15 (cluster power) and 23 (ground), this way the draw was only 100mA going through the ground (23) wire.

just to be sure/explicit, when i said "connected" to car ground, i meant connecting them with the voltmeter to measure voltage, positive lead on one of the pins, negative on the car ground.

[The Gonz]

just to be sure/explicit, when i said "connected" to car ground, i meant connecting them with the voltmeter to measure voltage, positive lead on one of the pins, negative on the car ground.

So the board lit up as you measured the bottom pins as a voltmeter? A voltmeter should have an impedance of at least 2MOhms, so there shouldn't be enough current to close the circuit. Not sure what's happening there.

[eLod]

just to be sure/explicit, when i said "connected" to car ground, i meant connecting them with the voltmeter to measure voltage, positive lead on one of the pins, negative on the car ground.

So the board lit up as you measured the bottom pins as a voltmeter? A voltmeter should have an impedance of at least 2MOhms, so there shouldn't be enough current to close the circuit. Not sure what's happening there.

yes, "connecting" any of the (used) pins from the bottom row on the 16p female to the car ground via the voltmeter  (to measure that ~12V) i see the lcd panel turning on.

how can i debug this further? my goal currently is to understand if the cluster board itself is faulty or the problem lies elsewhere.

[The Gonz]

If you know the pins that cause the drain, try tracing where they go off the board.

[eLod]

If you know the pins that cause the drain, try tracing where they go off the board.

well, i only had 3 small wires, and i saw 100mA [in that setup the whole drain was 100mA] go though the 23 pin (ground) on connector A, i ordered small cables, so hopefully i will be able to test it better. however if the drain goes to ground, is that something i should trace further (isn't it normal for current to go that direction, i mean the fault is in the board sending out that current no)? again sorry i am not familiar enough with circuits.

[The Gonz]

Your excessive current doesn't just go to ground. It starts at the battery and gets into the board. Seeing it on a pin that you are sure is connected to chassis earth does not provide you with useful information. You'll need to find where it's flowing on the board or back out to some other devices. In your shoes, I would hope for a 2nd car to swap boards and maybe cables to compare.

[eLod]

Your excessive current doesn't just go to ground. It starts at the battery and gets into the board. Seeing it on a pin that you are sure is connected to chassis earth does not provide you with useful information. You'll need to find where it's flowing on the board or back out to some other devices. In your shoes, I would hope for a 2nd car to swap boards and maybe cables to compare.

yes i would try with another cluster, but i don't know of anyone who has the same car. i tried to search for salvage yard prices, i found some clusters for relatively cheap (30-60 eur), but i don't know which part numbers are good for me (and i don't want to buy it just to see if drain is gone, but otherwise the cluster is not a match).

i have found a site which lists components but to my dismay it lists 14 different components for the same number 94033-2R500 with different configurations.

for debugging further: i am trying to understand how to best debug the issue. only connect the power in pins for the board and measure current through the ground pins, and if all current is there, follow those wires? try to connect the pins directly (eg leaving out the board from the circuit) and see if the drain is still there (so it's not the component what is faulty)? what i don't understand how it's only flowing (draining) depending on some control pins (10-14, says driver/passenger, rear lh, rear rh, i guess door open indicators?) connected.

[edit: corrected the part number]

[The Gonz]

only connect the power in pins for the board and measure current through the ground pins

Measuring current through the ground pins or through the supply pins should not give a different reading, but I would prefer to leave the ground pins grounded and work from the supply side.

try to connect the pins directly (eg leaving out the board from the circuit) and see if the drain is still there

That will create a short circuit, blow your fuses and tell you nothing.

what i don't understand how it's only flowing (draining) depending on some control pins (10-14, says driver/passenger, rear lh, rear rh, i guess door open indicators?) connected.

That is the real problem. The best you can do is isolate exactly which supply pin causes the current drain and then try to trace the voltage around the board, but without a schematic showing good detail like expected voltages, you have a challenge. Also, with only the supply pin connected causing the drain, check again for a hot spot. If 200mA are still flowing and it is not normal, then the board has the problem.

If not, then reconnect pins that lead to door switches, lamps, etc. until the drain returns, then it will point to the cable or device at its end.

[eLod]

so as i said earlier, supply and ground pins are in connector A, the problematic pins are in connector B, if i don't connect connector B at all, there is no drain (after the initial take up and 1 minute passed).

also there is not a single pin in connector B that by itself reproduces the drain (to be specific, whatever pin i connect, after the initial load and 1 minute passed it goes down to 0.01A reading for all configurations of a single pin). furthermore whatever i did i couldn't produce the persistent draw for whatever 2 pins combination, i have to connect at least 3 (from 10-14) to see the drain persisting after 1 minute. i have to connect 10+11+12, or 10+11+13, or 11+12+13, to be able to see it.

[The Gonz]

10+11+12, or 10+11+13, or 11+12+13

Where do these pins lead? Door switches? Indicators? Alarm module?

[eLod]

also i took a day off from work for tomorrow, hopefully i can debug this further

[The Gonz]

Door switches!
Are you seeing the excessive current flow through the door switches?
Is the insulation on the wiring to the switches in good condition?

[eLod]

sry for my ignorance, but can you be pls be more specific? are we talking about the push buttons on the driver door (eg the window up/down and central lock)? am i supposed to open/disassemble the door? when i measured no current flow was going on the 10-14 pins of the instrument cluster connector B. please talk to me as if i were a dumbass (which i am regarding to reading circuits).

[The Gonz]

You tell me. In the diagram each door switch is labelled with a corresponding photo. What does the photo show?

[eLod]

unfortunately i don't have the photos only the wiring diagrams

[The Gonz]

In any case, it might be useful to compare resistance to each of these switches from where it connects to the board. They should all measure fairly high (use the ohmmeter setting and measure from cable pin to ground.