Hello everyone,

I own 2016 Skoda Octavia 5E and I began to have a tailgate opening issues in November 2024.

 

What was it like?
Firstly my boot went up only a half way, then beeped and stopped. I could either open/close by hand, or pressed button again and then it closed automatically. After this it worked for a while normally. Then it could not open up automatically, but could close automatically with a press of any button once manually opened. Then it worked like that for about a month until it didn't work at all. Now if I press any button to open the boot (interior, key fob, trunk buttons) I can only hear one beep and that's it. I read errors with VCDS diagnostics and there was only "Electrical error Motor 2". I could read all the values from the control unit (CU) like motors' position or voltage.

 

I decided to buy new motors from ebay. Replaced them and it didn't work either. I read the CU again, no errors since the last time because I deleted them when I had old motors installed. I could again read all the values, however I noticed that voltage on motors was 1.85 V all the time, if I opened/closed the boot, I could see that CU is trying to work, but nothing happened and voltage dropped to 0 V, then came back to 1.85 V if the CU stopped trying to open it.

 

So what's next?
I decided to check the CU itself. I looked for some corrosion or burnt components on PCB but there was no obvious damage, when I connected the CU back I could even hear relays being turned on or off. Even though CU seems fine, and I can read it with diagnostics, it doesn't mean it's actually 100% working. I was checking the voltage only with VCDS, didn't measure it with a multimeter yet. I checked the wires too, no damage was seen. So after all of this I think that the CU may be faulty or burnt fuse? (If fuse was dead I guess more features would stop working). Or maybe locking mechanism is misbehaving and causing issues in control logic? I have read that even locking mechanism can cause this like in these videos: 

Do you have any tips what could be wrong or worth checking?

 

Good Afternoon, I have noticed I was having the same issue you are having. 
 

unfortunately I have noticed tips as just today my tailgate has stopped working altogether. 
 

My observations is that I get all information from my CU my switches, hall sensors all appear to be working. 
 

I have noticed that on the parameters using the VCDS, relative lid position is always 100% open or closed. And the “reason for open/closing cancellation is “position error”
 

I cannot perform any Basic settings as my boot will not even attempt to open. 
 

I am suspecting a failed CU. 

I have replaced the motor struts, lock and the tightener, all for different reasons. However, the problems you are describing sound like the time when the strut motors needed replacing.

 

OP told he replaced the strut motors with ones from ebay. What struts you bought from ebay?

 

@Skoda-scouting have you checked the wiring from the struts? Inside the rubber cover there is often broken wires, if the wire for motor position is broken it could falsely tell it is 100 % open.

@skodaaudi

 

The struts are 3rd party replacements, using the VCDS I can see the absolute position changing and the values for each struts hall sensors change.
 

What I’ve observed that despite these values changing as I raise and lower the lid the “Relative position”remains at 100%. 
 

The close assist does not work at all either. 
 

before this happened I was having very similar issues as the OP. 

@Skodaudi I bought these exact struts https://www.ebay.com/itm/166534060260

On 26/02/2025 at 22:02, Skoda-scouting said:

@skodaaudi

 

The struts are 3rd party replacements, using the VCDS I can see the absolute position changing and the values for each struts hall sensors change.
 

What I’ve observed that despite these values changing as I raise and lower the lid the “Relative position”remains at 100%. 
 

The close assist does not work at all either. 
 

before this happened I was having very similar issues as the OP. 

 

Ok I expected the relative position to come from the struts. For the lock position as percentages does not sound reasonable, there is just a on/off switch. The closing assist might have position transmitter. Have you tried if it moves with vcds and if this relative position changes? And have you adjusted the desired opening position for the tail gate after replacing the struts (open manually to desired height and then press the closing button until you hear a multitone sound), perhaps this can be related to the relative position.

 

Probably you are right with the CU, but I guess these are worth to mention.

 

@matrick173  Have you adjusted the desired opening position after strut replacement? Also, if you have someone with surely working struts try to swap his struts into your car to see if they are the reason. Such cheap random chinese struts might simply just not work.

 

Both, any 3rd party LED bulbs or other electronics anywhere in the car? Would not be first time they mess up boot communication.

@Skodaudi i don't know anyone who has OEM (or working) struts that I could swap. I also tried to set new open position by holding button on the trunk. I replaced a soft close mechanism but no difference. Is there any way to hard reset or reset or set factory settings to the CU with VCDS? I think that something is messed but in the sequence. The way it works now is as follows:

1. Press any button to open.

2. Lock unlatches and trunk slightly pops up.

3. CU beeps once.

4. nothing.

5. I open up trunk manually.

6. After ~20cm of travel the soft close moves up (as in videos above).

 

Is there a way that the CU can be faulty and yet I can read/write values to it?

@Skodaudi I am the second owner of the car, previous owner had installed LED license plate lights instead of halogen bulbs, they started flashing so I replaced them with halogen light bulbs that I had at my disposal and later installed brighter LEDs with resistor so car doesn't detect license plate light error. My interior lights are all aftermarket LEDs.

 

Are the LEDs from superskoda/kopacek or ebay/aliexpress type of leds? Especially roof leds might mess up with boot. If they are some cheap chinese kind of, they might be the cause. Try to swap oem bulbs to see if that helps. The boot problems might start even like one year after swapping to aftermarket leds without enough resistance.

Idk if it possible to 'hard reset' the CU. But yes, it can fail partially and still seem to operate fine. However in such case there is good change to visually see damage in the board or so, which you already checked.

 

One more thing what might be the cause in both cases is the opening button / release handle in the boot. They fail some time and prevent opening even by key fob and cabin button.

@Skodaudi All the interior, boot space and license plate LED lights are from Aliexpress. I will try replacing them with Osram W5W halogen bulbs that I got spare. Do you think I should remove the LEDs, or replace with Osram bulbs entirely. Can you please elaborate more on how these LEDs can mess up boot opening or point me to a thread where this was discussed? I'm really interested.

What I'm gonna do is to replace LEDs with Osram bulbs, disconnect the battery for a couple of minutes, reconnect and try to open/close the boot. Do you think it's a good procedure?

Edited 2 March, 20251 yr by matrick173

It has something to do with lower resistance of the aftermarket LEDs, somehow messing up the boot CU. Here is two threads, however it is about faulty boot open warnings, but it comes from boot CU right?

https://www.briskoda.net/forums/topic/490826-the-most-bizarre-lighting-issue /

 

Also check this:

 

Your suggestion sounds reasonable. I guess disconnecting the battery is also the best possible reset for the CU without better tools / knowledge.

Edited 2 March, 20251 yr by Skodaudi

48 minutes ago, Skodaudi said:

It has something to do with lower resistance of the aftermarket LEDs, somehow messing up the boot CU. Here is two threads, however it is about faulty boot open warnings, but it comes from boot CU right?

LEDs take less current so are higher resistance not lower resistance.