Dabber2024

Well here I am again and its time to pick this problem back up. So the gripping tale continues, as of last march I had put switched power to my radio to reduce the battery drain with the intention to perform further diagnostic with the arrival of a logging clamp meter, this is a bluetooth enabled DC volt clampmeter which allows me to measure current flow in a wire over a period of time in a table and graph. Given the previous information I gleaned regarding the water leaks from the rear washer jet causing a short in the rear wiper motor I was planning to clamp the power leads going into the wiper motor and see if there was a spike when the motor kept trying to "park" the wiper blade (as per stuff ive read on tinternet). Naturally the clampmeter has arrived and ive still not got to grips with it lols. I have had a quick go using it on the rear wiper motor leads but i need to get in and have proper go. So the reason for this update. Mavis (our fabia) suddenly decided to stop responding to the key fob this week, i changed the battery and that didnt fix it, i then noticed that the little red light on the key fob was working anyway so clearly its not the fob, or at least the fob is good for power anyway. The spare fob also failed to operate the locks. It has been raining heavily in our area this last week after the prolonged hot weather I should add. We have therefore been locking and unlocking the car with the key, when doing so the only lock that opens is the drivers door lock, in order that we can open the boot i have to press the centre console mounted lock/unlock button and then go and open the boot as normal. When i press this lock/unlock button on the centre console (below the radio area of the dash) it makes an interesting pair of noises, normally it makes an unlock noise followed by the different and sort of "heavier" clunk of the deadlocks coming off, now it makes the initial sort of whining click noise and then repeats itself as if its started an operation and then reversed itself by performing the same operation. Its hard to describe but it now makes two noises that sound the same rather than the correct two noises that are distinctly different. Additionally at no point has the central locking activated itself to unlock any of the other doors, we have to use the internal handles to unlock them. As you can imagine I have by now read many many articles on door locking and electrical gremlins, including @Breezy_Pete interesting article on reflowing the solder joints in the door lock where his earth joints were cracked. This article also ed in with something I read about the shared earth of the door lock unit contributing to the door button for disabling the internal alarms malfunction. I have also read many articles on wires in the door cable grommets being cracket or broken and the issues these cause which can be varied. As mention previously I also am pretty sure my rear wiper has been leaking over my rear wiper motor (theres a lot of rusty deposits and rusty number plate lights apertures) and causing the failiure to park problem which could be triggering a battery drain. However the one thing I have not read so far in this saga is the most recent trick Mavis has pulled. Basically having locked up with the key earlier today I came down around dusk to go for a drive in Mavis, only to find that the drivers front headlight and drivers rear running light were turned on !!! Note i say drivers side ONLY. The car was still locked and I dont thing the little red light on the door was flashing to indicate the alarm is on was blinking but couldn't swear to that. At which point my wife clicked the key fob opne button that hasnt worked for 5 days now, and the bloody car opened up !!! All the doors !!! I have never seen this one sided malfunction occur before in my life, it is possible in my Talbot Talisman for this to occur because the right and left side of the vehicles lights go through different fuses and the main operating switch must send power to both fuses. Are Fabias wired up so that the drivers side lights go through a different fuse than the passenger side ??? And even if they do how on earth is it possible that power can flow to the lights when the car is locked and the key not even in the ignition ??? Somehow the car has turned its own lights on and unless the ECUor Body Control Module actually perform part of the power switching task between the manual switch and the light bulbs then I cannot see how this is possible ............UNLESS somehow power has been flowing from a short to the lightbulbs Thoughts anyone ?? Dabber

This was the video ! Excellent knowledge that man. New alarm has arrived need to get round to fitting it. Update on TOPDON carpal readings...retested today after clearing all codes previously. The alarm missing code is back...and also the passenger door inaudible signal ! so.. hypothesis time... The old owner had a dodgy door close signal This set the alarm off intermittently They decided to remove the alarm The door locking signal fault is still there The ECU brain is searching for the Lin wire thats commuinicating with the (missing) alarm The ECU brain is now confused and somehow keeping the radio turned on in the background When I clean and refit the alarm siren I expect to get it going off intermittently but I wont delve into the inaudible door signal fault till I have seen if the radio parasitic drain goes away .. Watch this space

Im not sure Pete, quite possibly , do you have a link please ? I would like to get some more knowledge as re-flowing the soldered joints is something I can do easily enough. Ta Dabber

Hi Alasdair, thanks for the input, i had not considered the possible shared power supply to the siren. As it stands my siren was missing when I looked the other day, pretty annoying. The new one off Aliexpress is on its way !. So todays update is only to show what happened when I ran a scan using the TOPDON CARPAL. This is an obd2 scan tool with additional car specific libraries of info you can download and use, they have good reviews . I ran the first scan below and there were several error codes which my old school code reader would not have been able to see. I have attached the detail of the codes as 1st scan details pdf and theres lots of implausible signal codes and an airbag code and then theres the 01134:004Alarm horn - No signal/communication Active/Static. Its the only code that was written in Red, the rest of them had text to tell me they were ok to ignore. So I performed a DTC code clear and re-ran the scan and the only one left was the Horn code. So, Im hoping that the old codes are indicators of some dodgy alarm related triggers from the door locks or something and the airbag code might be something from someone else doing work on the car. When the new siren arrives I will get it plugged in and try it. There are 3 wires from the alarm siren earth, power and a communication wire which is either Lin Line or K line (not sure), I should be able to trace the signal wire back to the combined Voltage control Module/Body Control Unit (i hope). The possibility that the control wire is keeping everything awake is well documented either by ways suggested by Alasdair or otherwise. Dabber 1st scan.pdf

Hi Pete, agreed on the microswitch. I cant find the post I read about the car door locking unit which pointed me towards poor soldering in the unit. What with the interior sensor disable button not lighting orange when pressed and the iffy pattern of flashes of the little red indicator light on the top of the door card somethings amiss. Went to look round the breakers yard for a fabia alarm siren , none present, checked several golfs as well and passats , could not even find the alarm sirens on them ! i was looking under the front panel below the windscreen and also the drivers wheelarch , most odd, i must be lokoing in the wrong place. Anyhow I guess i will have to actually buy one from Aliexpress.

apologies

@JR RS Judging by the dash display the door close and open switch is working, thats not to say it doesnt need cleaning at the least though, which I will do. Octavias might work without an alarm siren but I would like to have a working car alarm on my fabia and from the many other fabia posts and sites I have studied the dodgy alarm battery or link does cause a battery drain, possibly through the 3rd control wire in the connector plug. At present my time only allows for brief periods of work so no taking of the door to pieces yet. I will check the door bellows next all round the car. I am working on installing VCDS lite just need a microsoft PC first and apparently a cable (usb to OBD2) not all cables work though so need to get one that reads the K line it seems. @Breezy_Pete Thanks for the part number, I will be looking at sourcing one asap, there are options from Ali express i believe but to be honest my local scrap yard will be the first place to go I think to get OEM, then perform a battery replacement on the part if required. I am hoping to find a 1K0951605F on a newly scrapped recent model if it is now the VW go to part number, maybe its on the new octavias ? who knows. Fix alarm horn first Investigate bellows Check for parasetic draw again Arrange day to take door to pieces and look at the microswitch possible open the controller module to check the solder connections as there is an interesting post around the earth causing trouble regarding the interior door alarm sensor disable button. From the research done so far the interior sensor deactivation button should be lit red then turn orange when pressed to indicate it is in action. I might visit the skoda garage to see another fabia in action. Dabber

Hi there, ive just been searching for "skoda fabia part number nomenclature" I spent 3/4 years working in the engineering department at Bentley as the go to man for parts and tools etc, the naming structure (nomenclature) of the VW system was adopted when they took over the company just after I started. The link below will get you started. https://www.darksidedevelopments.co.uk/Blog/vw-part-numbers-explained/ There is also a full skoda parts list which you have to pay to access, you can run a parts list by VIN number apparently from this : http://www.partslink24.com/ I have just discovered (thank you @Breezy_Pete ) that the horn to fit my fabia was part 1K8951605B, which has been superseded by 1K0951605F. Which is interesting as the first three digits 1K8 indicate: 1K = Volkswagen Scirocco (2009 - 2014) 8 = Coupe from https://vagupdate.com/blog/vag-part-number-structure This has been superseded by the 1K0 1K = Still VW Scirocco 0 = Not specific to LHD or RHD models Things to consider here, and this comes from my years working within engineering at Bentley This is an alarm siren, it has no reason to be handed i would say. Also VW group will not allow engineers to create new part numbers on a whim, there is a strict part release process (3 stages in TEVON system? ) which ensures no new parts are designed when one exists already across the VW group. Its costs many thousands of pounds to revise a BOM, Drawing, Stock holding, part number etc, so they wont do it if possible. Providing the designation 1k as a VW Scirocco is correct from those other sites I am guessing that at design phase of the MK1 fabia the designers were given a packaging space within which they could use the VW Scirocco siren and told to get it fitted. Given there was no requirement to make a handed part (which in practice generally means a model specific part like a wing for example) they did exactly that upto at least Rev B on the MK2 possible later. Then along came the need to supersede the original part number to 1K0 which I am thinking means the part has been moved to another area of the BOM not specific to LHD or RHD models and will be used going forward as the standard VW alarm siren until the physical shape or function is forced to change by outside design factors. good luck Dabber

@Breezy_Pete @J.R. Comments noted and will check the alarm fuse. The radio does indeed work, and I am looking at getting a vagcom connector and downloading VBCDS-lite Update: Following from my previous entries I am pursuing the course of least resistance and have now re-routed the 12V power to the radio from its original fuse (50) and have taken a power lead from fuse 1 (micro fuse) bus rail, which is switched. So now at least I dont have to keep whipping the fuse in and out. Next I took a look under the front scuttle for the alarm siren horn.....guess what....no alarm siren present, the wire and connector plug was lying loose in the scuttle but the horn has been removed, looks like someone mangled the bracket slightly as well. See attached. I stated on https://www.briskoda.net/forums/topic/525881-alarm-interior-sensor-shut-off-switch/ this post that my drivers door indicator light was also showing an error somewhere in the central locking ref the flashing sequence of the little red light at the top of the drivers door card. So my thoughts are now running to there being a central locking issue, triggering the alarm all the time, so someones removed the alarm, and now my battery drains and the central locking is not always working right. So 1st this means I need to buy the alarm siren, which means the right part number , my best guess so far is 1K0 951 605 C for the part number based on looking for internet sales for fabias from 2011. I could do with this confirming however if anyone happens to know the correct part number for a skoda alarm siren ? Thanks Dabber

@cbeds7 Appreciate this is an old thread however I wanted to share a bit of info I just gleaned: from this link https://www.b-auto.net/skoda_fabia-1/central_locking_system-747.html God bless em. Warning light in the driver's door After locking the vehicle, the warning light flashes for around 2 seconds in quick succession, afterwards it begins to flash evenly at longer intervals. If the vehicle is locked and the safe securing system » page 46 is not operating, the warning light in the driver door flashes for about 2 seconds fast, goes out and starts to flash evenly at longer intervals after about 30 seconds. If the indicator light first flashes fast for about 2 seconds, then lights up for about 30 seconds continuously and then flashes slowly, there is a fault in the central locking system or in the interior monitor and in the towing protection » page 50. Seek help from a specialist garage. I know this doesnt answer your question but bare with: Basically my mk2 1.6 tdi has got a red light like yours in the drivers door to turn off the interior sensors, mine lights up red as I open the door, I press the button, it goes out but comes back on again, after a short time it goes out permanently. I then move about in the car and the alarm doesnt trigger. Before placing any faith in the button I have to first repair the horn unit in mine because it doesnt make any noise, the indicators do flash however which is whats telling me that the interior sensors are indeed being turned off..HOWEVER the section of text in red above is whats happening to the little red light at the top of the drivers door card so clearly I have a central locking problem which is maybe why my Interior Sensor Off button is showing symptoms like yours of being lit red when logic would suggest it shouldnt be untill pressed ? thoughts ? Oh ive also read on this forum that the central locking, little interior sensor button, alarm horn etc are all wired together and sharing earths inside the door .....

Well J.R., i need to find a reason as to why the battery drains 3.5 V over 4 days , theres nothing ghostly about that. It may be that the fault does not lie in the CANbus but as per the table below from right at the start the values for power draw are above normal (quiescent ? ) Situation 2 & 3 No. Power consumer Fuse rating (A) Fuses in our box With engine running (mV) Converted using fuse chart to mA Engine off, bonnet and door latches locked and car locked, after 1 hour (mV) Converted using fuse chart to mA 22 Operating controls for the heating, control unit for air conditioning system, parking aid, mobile phone, instrument cluster, steering angle sender, ESP, vehicle voltage control unit multifunction steering wheel 7.5 mini fuse 7.5 mini fuse 4.6 mV 424 mA 0.5 46 mA 24 Central control unit of the vehicle 5 mini fuse 5 mini fuse 3.9 mV 220 mA 2.6 mV 146 mA 49 Turn signal lights, brake lights 15 big fuse 15 big fuse 0.1 mV 21 mA 0.1 mV 21 mA 50 Radio 10 big fuse 10 big fuse 4 mV 519 mA 3.9 mV 506 mA Some more study on you tube diagnoses the curious equal voltage values on can hi and low of 2.51 V in my test 8, they were static values on the meter with no fluctuation, as described at 15:00:00 in this video https://youtu.be/JicbzR3Juh0?feature=shared this might indicate can hi and low are shorted together, so Mr Diagnostek says to perform a resistance test between can hi and low at the OBD, in his video he gets a 0.2 Ohm resistance instead of 60 ish Ohm and hes suggesting that means the can bus wires are shorted together rather than to ground as he also had equal static voltage values. In my readings my OBD can hi and low resistance check gave me a good 60 ish ohm reading BUT my resistance check at the RADIO plug gave me a 0.1 Ohm when really it should have been 60 ish ohm (according to the other video https://youtu.be/fZMNzKpCGfc?feature=shared here.) I shall research alarm horn issue and also remove the J519 module as I might be able to at least split the two CANbus systems and determine something more. Ultimately I have to fix this car otherwise my wife will get anxious driving it and I am not having that, perhaps this level of diagnostics is a bit much for an amateur but the battle is far from over - cue bugles and the sound of the Light Brigade

Small update on the radio parasetic drain. Based on my belief that there is a short to ground on the radio canbus somewhere i took a look at the radio wires, they were fitted badly and part of the loom where it disappears to the right of the radio was slightly damaged. One of the black radio aerial wires was showing bare silver wire and also the earth wire (brown/yellow) that terminates in pin 12 ( Voltage supply, negative, terminal 31) So i taped these up in the vain hope this might be the cause of a short. It didnt seem to be, i refitted the stereo and after 30 mins tested the current drain again and the radios still pulling voltage. Ref Pete i felt along the loom and can feel the bulge where the radio wires join the main loom, can see it of course 😞 still good to know where it is. Before I get to removing the dash I am wondering if it is some other module thats giving the whole system the yips as it were and Ive come across videos of similar battery drains being caused by the alarm horn. Interestingly on the times that I have been testing the car I have had the door and bonnet locks tricked waiting for the CANbus to go to sleep and when I opened the door to get in the indicators all started to flash, BUT no horn sound ! so Im now wondering if the alarm horn is up to no good, thanks to some advice I can see the Horn for the alarm is not on either the CAN line however hmmmmm. My mate has a mate in Northwich who is a auto tech and we shall take the car to him one saturday to see if he has a tool that can run a diagnostic and show the topology map of the CAN bus lines, if he has all the gear then that night rule out the radio, though the short to ground is still there, im going to check that tomorrow when I switch batteries I think ,make sure I wasnt seeing things. Dabber

Cant thank you enough Pete, im going to look at that now. For anyone interested heres a link to a site with lots of workshop manuals and diagrams on every VW group car out there ! https://www.vag-hub.com/fabia/fabia-mk2/

Any thoughts on the above post would be welcome, tomorrow I shall start stripping back the can bus wires from the radio as I believe the ground short is causing other modules like the Voltage control unit to misfire and stay awake, in turn this is keeping the radio on which enhances the battery drain. I still really need a diagram of the canbus network and the points at which I can split the loom to test the separate parts. I found this which is maybe for an octavia. ive also just found this: on another source.

Hello all Back to it today and starting from the top with a fresh battery. Firstly i need to answer @Breezy_Pete I tricked the car locks and left the car for 30 mins or so and took readings across the fuses as you suggest. fuse 24 was giving a reading of 3.5 mV, this is the central control unit fuse. fuse 22 was also giving a voltage of 0.5 mV this is the voltage control unit fuse amongst other things. Fuse 50 (radio) was no longer giving a reading, the radio was not fitted for this test. The battery was still depleting but at a much slower rate as previously mentioned in my posts. So it seems the radio is not the only source of the drain. I next went through the tests from the video but jigged the order, first i left the battery negative cable off, then i attached the battery neg cable but left the ignition key out of the barrel, then I did the tests again with the ignition on. The results are tabulated below. The first thing i noticed was that the 66.6 Ohm reading between can hi and lo at the obd2 port was not repeated at the radio multiplug which I have a feeling it should have been The next thing I noticed was the constant voltage of 2.51 V on both can hi and lo at the obd2 port with the battery connected, my understanding was that can hi should have read 2.58 ish V with Can lo reading 2.4 ish V. Im not sure what to make of all this other than, the main spine of the canbus is intact, the radio spur from the canbus gave a reading of O.L which is wrong. So my thinking is the canbus leads from the radio are broken prior to joining the loom. I also think there is a voltage short present somewhere, maybe at the same point. Test number Test purpose Notes Result Further questions Test 1 Establish battery voltage Fresh fully charged 12.9 V Test 2 Ignition off battery not connected Is the CAN network asleep. At the OBD2 port. Check voltage between AN hi and CAN low pins 6 and 14 on the latest CAN design (post a2008 ? ).Reading should be 0 V if network is asleep 0 V No battery connected..no power anywhere Test 3 Ignition off battery not connected Resistance check of the network at the OBD2 port and the terminating resistors. Test between CAN hi and CAN low There are two resistors built into the two modules at the two ends of the network, they are 120 Ohms each. Measure resistance between pins CAN hi and CAN low pins 6 and 14 should be 60 Ohms 66.6 Ohms So the main spine of the CANbus is in one piece If you get a GOOD 60 Omh reading It could still be a module has a break in one of its CAN wires, providing the module is Not a gateway module OR it doesn’t contain a terminating resistor Resistance check of the network at the radio multiplug can hi and lo. Test between CAN hi and CAN low Measure resistance between pins 9 CAN hi and 10 CAN low, 0.1 Ohms Given the main spine is reading 66.5 Ohms I was expecting to read that at the radio plug, am I correct in this presumption ? From the video notes they say, providing the radio is NOT a gateway module or has no terminating resistor then this test when performed at the OBD2 port would indicate a possible break in the Radio CAN wire or other module Test 4 Ignition off battery not connected Short to ground at the OBD2 port– You cant test resistance with current flowing Set to Continuity and check between Chassis Ground (pin 4) and CAN hi and low. If ANY CONTINUITY IS DISPLAYED THEN THERE IS A SHORT TO EARTH ON the circuit somewhere. If YOU GET 60 Ohms on both CAN hi and CAN low then thats good Pin 6 CAN Hi 14.41 kOhms Pin 14 CAN low 14.41 kOhms Short to ground at the Radio multiplug CAN hi lo Set to Continuity and check between pin 9 & earth and pin 10 & earth, Pin 12 used as earth Pin 9 CAN Hi 3.64 MOhms Pin 10 CAN low 5.8 MOhms Value kept climbing on the scale , no continuity beep Test 5 ignition off, battery connected Check voltage at the OBD2 port Set to DC Volts and check between Chassis Ground (pin 4) and Pin 16 power, should get the battery voltage reading 12.9 V Test 6 ignition off, battery connected Is the CAN network asleep. At the OBD2 port. Check voltage between AN hi and CAN low pins 6 and 14 on the latest CAN design (post a2008 ? ).Reading should be 0 V if network is asleep 1 mV How can the meter measure voltage BETWEEN the two can hi and lo pins ? They both carry voltage normally when awake and to measure the voltage the electricity has to flow to earth doesn’t it ? Is the CAN network asleep At the radio mujltiplug. Check voltage between pin 9 can hi and pin 10 can low 3.5 to 4.9 V Value was fluctuating Test 7 ignition off, battery connected Check voltage at the OBD2 port Set to DC Volts and check between Chassis Ground (pin 4) and Pin 16 power, should get the battery voltage reading 12.88 V Test 8 ignition off, battery connected Short to voltage at the OBD2 port Set to DC Volts and check between Chassis Ground (pin 4) and CAN hi and low. No voltage should be displayed if the BUS is asleep. If you get voltage then theres a short to voltage somewhere Pin 6 CAN Hi 2.51 V Pin 14 CAN low 2.51 V Static value no fluctuation. Short to voltage at radio multiplug can hi lo Set to DC Volts and check between CAN hi pin 9 & earth and CAN low pin 10 & earth. Pin 9 CAN Hi 0.59 V to 0.8 V Pin 10 CAN low 4.3 V to 4.9 V Value was fluctuating Short to ground at the OBD2 port– You cant test resistance with current flowing but tried it anyway Set to Continuity and check between Chassis Ground (pin 4) and CAN hi and low. If ANY CONTINUITY IS DISPLAYED THEN THERE IS A SHORT TO EARTH ON the circuit somewhere. If YOU GET 60 Ohms on both CAN hi and CAN low then thats good Pin 6 CAN Hi O.L no buzzer sound Pin 14 CAN low O.L no buzzer sound Short to ground at the Radio multiplug CAN hi lo Set to Continuity and check between pin 9 & earth and pin 10 & earth, Pin 12 used as earth Pin 9 CAN Hi O.L no buzzer sound Pin 10 CAN low O.L no buzzer sound Test 9 ignition ON, battery connected Is the CAN network asleep. At the OBD2 port. Check voltage between AN hi and CAN low pins 6 and 14 on the latest CAN design (post a2008 ? ).Reading should be 0 V if network is asleep 0.9 mV How can the meter measure voltage BETWEEN the two can hi and lo pins ? They both carry voltage normally when awake and to measure the voltage the electricity has to flow to earth doesn’t it ? In this test obviously there is no battery connected but later Is the CAN network asleep At the radio mujltiplug. Check voltage between pin 9 can hi and pin 10 can low 3.49 V to 3.52 V Value was fluctuating Test 10 ignition ON, battery connected Check voltage at the OBD2 port Set to DC Volts and check between Chassis Ground (pin 4) and Pin 16 power, should get the battery voltage reading 12.53 V Short to voltage at the OBD2 port Set to DC Volts and check between Chassis Ground (pin 4) and CAN hi and low. No voltage should be displayed if the BUS is asleep. If you get voltage then theres a short to voltage somewhere Pin 6 CAN Hi 2.53 V Pin 14 CAN low 2.53 V Static value no fluctuation. Short to voltage at radio multiplug can hi lo Set to DC Volts and check between CAN hi pin 9 & earth and CAN low pin 10 & earth. Pin 12 used as earth Pin 9 CAN Hi 0.71 V to 0.75 V Pin 10 CAN low 4.27 V to 4.23 V Value was fluctuating