Been having problems with battery on my 2017 2.0 diesel recently: it's had to be jump started several times in the past 3 weeks. I've no discovered the problem: the radiator fan coming on very fast, and randomly, with the engine switched off. This can happen even with the engine completely cold after being stood for hours. Any experts have any ideas what could be causing this?

Cheers!

"no discovered" = "now discovered"

5 minutes ago, Johncee said:

"no discovered" = "now discovered"

See the ellipsis "..." characters top right of your post? They'll give you an edit option for a hour or 2.

37 minutes ago, KenONeill said:

See the ellipsis "..." characters top right of your post? They'll give you an edit option for a hour or 2.

I did look there, but only saw the options "report" and "share". Maybe because I'm a newish member?

@Johncee

please note, mine is 2.0 TSI

  

On 12/06/2020 at 18:29, MartiniB said:

Long story, 5 service visits to solve

https://www.briskoda.net/forums/topic/422971-cold-engines-fan-high-spin/

 

@MartiniB

Thanks for the info. The intensity of the noise made by the fan is similar to your video in the thread you linked to.

 

But mine does this even with the engine switched off....

It can be sitting parked, completely turned off, engine completely cold and "whoosh" off it goes at random. 

 

I wonder if your car is trying to do a force dpf regen?

 

The fact you mention the battery needs charging i’m guessing you’ve not used it a great deal.

 

If I were you i’d wait until it next does it when you turn the engine off then start it again and go on the motorway in 3 or 4th/4th or 5th for about 15 minutes at least.

 

I can’t remember what gear the manual says to go in to increase the revs to above 2k, I’ve got a dsg so it down gears a few automatically.

 

If it’s not that, apart from something electrical causing the issue it could be your engine oil needs replacing

7 hours ago, Danoid said:

I wonder if your car is trying to do a force dpf regen?

 

The fact you mention the battery needs charging i’m guessing you’ve not used it a great deal.

 

If I were you i’d wait until it next does it when you turn the engine off then start it again and go on the motorway in 3 or 4th/4th or 5th for about 15 minutes at least.

 

I can’t remember what gear the manual says to go in to increase the revs to above 2k, I’ve got a dsg so it down gears a few automatically.

 

If it’s not that, apart from something electrical causing the issue it could be your engine oil needs replacing

Don't think it's to do with dpf regen. Although I'm happy to be corrected.

This doesn't seem consistent with the fan coming on randomly sometimes when the car has been sat on the drive with the engine switched off for hours.

Also nothing to do with lack of use. Last time it happened was yesterday evening, a couple of hours after a 120 mile motorway drive. The fan came on, and wouldn't stop until the battery ran out of juice...

It's a very intermittent thing. Can go for weeks without this happening. I fear this will make garage diagnosis a nightmare, unless this is a well-known problem...

 

Edited 12 August, 20214 yr by Johncee

If there's an electrical connector on the fan that you can get sufficient access to unplug, inspect it for signs of water ingress and/or corrosion of the contacts inside.

 

There's a permanent 12V supply which may be getting shorted to other pins that are causing the fans to spuriously burst into life.

 

 Whilst there, check for wiring damage adjacent to the connector too.

 

 

 

 

In case it's any help to anyone in the future, the cause of this problem turned out to be a faulty relay (the 645 one in the engine bay fuse box), which was discombobulating the ECM.

 

Did a Carista scan, searched the fault code in this forum and found that a very helpful user called Bob3 had experienced and sorted the very same problem.

2 hours ago, Johncee said:

In case it's any help to anyone in the future, the cause of this problem turned out to be a faulty relay (the 645 one in the engine bay fuse box), which was discombobulating the ECM.

 

Did a Carista scan, searched the fault code in this forum and found that a very helpful user called Bob3 had experienced and sorted the very same problem.

Nothing worse than someone with a problem then never getting back with an update, so kudos to you 🍻

On 11/08/2021 at 21:40, Johncee said:

@MartiniB

Thanks for the info. The intensity of the noise made by the fan is similar to your video in the thread you linked to.

 

But mine does this even with the engine switched off....

It can be sitting parked, completely turned off, engine completely cold and "whoosh" off it goes at random. 

 

This only happened to me yesterday. 2016 190tdi. I parked the car in the garage and after a while I heard the fan running, thought it was a regen but odd that it started after car was switched off. It kept going so I realized it wasn't a regen as that normally results in a smell. Anytime I opened the drivers door the fan stopped. Once the door was closed for 20/30 seconds it came back on. The fan kept running so I parked the car outside and then it stopped. Later that evening I switched on the ignition and the low battery warning triangle flashed up. I turned the ignition off and on again and no warning. Car started fine today and no issues. Battery has never given any problems either. Maybe the relay is thinking about dying! Interesting to find this post👍

Edited 18 December, 20214 yr by Markbro

11 minutes ago, Markbro said:

This only happened to me yesterday. 2016 190tdi. I parked the car in the garage and after a while I heard the fan running, thought it was a regen but odd that it started after car was switched off. It kept going so I realized it wasn't a regen as that normally results in a smell. Anytime I opened the drivers door the fan stopped. Once the door was closed for 20/30 seconds it came back on. The fan kept running so I parked the car outside and then it stopped. Later that evening I switched on the ignition and the low battery warning triangle flashed up. I turned the ignition off and on again and no warning. Car started fine today and no issues. Battery has never given any problems either. Maybe the relay is thinking about dying! Interesting to find this post👍

Sounds very much like the problem I had. It'll drain the battery if it happens when you aren't around to hear it, and do whatever makes it stop.

If you can do an OBD scan, the fault code that indicates a relay problem is P086B. 

 

Just adding to this thread that I had the same problem with the radiator coming on at random (would cut in when parked) and behaviour not consistent with DPF regens. Car was at times reluctant to start with prolonged cranking (possibly because battery run down from fan? Or effects from the relay failing - not sure). 

 

My car is a 2018 TDI 190 4x4 Estate 30,000 miles. 

 

OBD Error Code: P068b ECM/PCM Power Relay De-Energized Performance – Too Late.

 

Following advice from this thread I replaced both relays marked 645 in the engine bay fuse box (I think it's the relay nearest the front of the car marked on wiring diagrams as J271 that was causing the issue but wasn't 100% sure so did both!) Seems to have resolved the issue. 

 

Purchased Bosch Relays from amazon. The OE part was made by Hella but not sure it really matters. Very easy to swap out, just like a big fuse. 

 

OE Part Number: 4H0951253A

Bosch Part Number: 0986332040

 

https://www.amazon.co.uk/dp/B0068M38ZI/ref=cm_sw_r_apan_glt_i_EAH5N4RM0FP0YZHPW4XN?_encoding=UTF8&psc=1

 

Photo attached.

 

Hope that the above info helps add to the info on this as I found this thread really useful to resolve the problem. 

 

 

Edited 10 February, 20224 yr by Vidmor

Hello I'm having this problem for a Wilde and purchased the wrong part , because autodoc send me to part 0986332002 this part  does not fit, so be carfull.

 

This is the one i have - 4RA007791-20 and i'm waiting for bosh part 986332040.

 

 

 

 

Edited 18 August, 20223 yr by Camarao69

Hope you get it sorted soon! 

Thank you thank you thank you!!!

Just had this exact issue yesterday. Moved car 200mtrs and parked up - found fan running maybe an hour later. Remote would not unlock doors despite several attempts. Eventually doors unlocked. When I opened a door, fan stopped. Closed door fan restarted. It ran till battery was flat. 
This morning, I took the advice here and went for the relays marked 645 in the engine bay fuse box and replaced them. Jump started ok and I have engine warning and limp home power. Maybe mine was trying to do a regen yesterday?? I’ll need to get out for a good drive at high revs to try resolve it. I hadn’t had an engine warning light before. Car has over 400k kms. 

Bumping this thread.

Hi everyone. New member of the Skoda family (approximately 3 weeks).

We bought the car (Mk III Superb L&K 2.0 Tdi 190bhp) which was delivered on a Wednesday. Went to use it on Sunday (other cars in the household) and the battery was completely flat. Had the battery replaced and 10 days later it was completely drained. We heard the cooling fan running constantly and unlocked the car, it stopped. Started and ran the car for a couple of minutes and went back inside. 

02h00 in the morning, the cooling fan came on and the alarm went off. Battery was so flat we had to use manual key (very fun for the first time in a heavy drizzle at 02h00!)

Anyway, the new battery was completely mothered. Found this forum and traced the problem straight to the 645 relay which was running hot compared to the other two. Thank you for that. 

HOWEVER, the big difference is our usual mechanic was picking up a lot of errors on the OBD so was trying to work out the cause for the fan coming on. To cut a long story short, we swopped the 645 relays around and all the relays worked but whenever one was put in the position of the heated relay, it too would heat up implying that whatever it is connected to (that switches on the cooling fan) is the fault as opposed to the relay switch itself.

So, any ideas what it is? The car is still within 30 day warranty and is booked into Skoda for diagnosis but they could only manage 19 September. I am hoping they have an auto electrician on the team as OBD shows a number of issues (possibly caused by the flat battery) one of which is the driver memory seat and we have problem with the start button which sometimes works first time other times needs to be pressed 2/3 times or held and then pressed to both switch on or off. Is that normal?

 

Apologies for the length and possibly arbitrary details. The short question is does anyone know what systems are on that third 645 relay switch 

 

Many thanks

EB

Just to bump and update this. Trying to speak to a Skoda technician but in their report, apart from faulty memory seat switch or controller and faulty start stop switch, they highlighted that we have a heated windscreen switch but the windscreen is not a heated one.

 

Rooting around here, I noticed that there is a thread about retrofitting a heated windscreen and they specifically mention them notorious 645 relay.

 

So, I am surmising that this was recently replaced with the non heated windscreen and a circuit is not closing or the ECU is constantly pinging it and causing excessive battery drain. 

 

How the cooling fan comes into play I have yet to ascertain but it may all be on the same circuit. 

 

Anyone with some knowledge care to weigh in?

 

Regards

 

EB

Just to follow up on this thread as it may be useful for someone in the future.

Despite telling Marshall Skoda Harlow what the problem was, writing down the list and leaving it in the car and suggesting they get in an auto electrician, they decided to ignore everything. 

They ultimately just replaced the 645 relay despite my warnings that the actual slot was causing the relay placed there to heat up when we swapped them around. "All fixed". But it wasn't as the cooling fan started again within about three weeks.

Then they replaced the memory seat controller and module. "All fixed". But it wasn't. The seats refused to accept new memory positions and wing mirrors did not adjust. This was over an extended period between October and November,

 

Took it back and the brought in Skoda Technical Team who advised that the boot module for the Virtual pedal was faulty and causing all the other systems to play up as they are all connected via some bridge. Personally, I have always thought "the ankle bone is connected to the shin bone" and not the shoulder bone but what do I know!!!

They took it back in Mid December to replace the boot module. As of today,  It remains there for 5 weeks although they have just said it is now fixed and ready for collection.

This entire thing has taken them from first week of September until now so approaching  5 months. The car is now out of warranty and we have only used it for three weeks and about 1000 miles (a fair lot of which was driving up and down to them  8 times and runs to recharge the battery three times).

Hopefully, this may be of use to someone in the future.

EB

On 17/12/2021 at 10:17, Johncee said:

In case it's any help to anyone in the future, the cause of this problem turned out to be a faulty relay (the 645 one in the engine bay fuse box), which was discombobulating the ECM.

 

Did a Carista scan, searched the fault code in this forum and found that a very helpful user called Bob3 had experienced and sorted the very same problem.

My Superb TDI is just sitting in the garage doing it again - and found this - could be handy ! Thanks!

I have same problem with my skoda. After I change the 645 relays everything look fine. Thank you for the advise.

Mine broke 1 week ago,fans started to blow even after 4 hours since the car was parked.

new OE 645 relay and is fine now

Can someone please tell me which relay is it that this fault is relating to the one at the top of the image previously shown or the one at the bottom?

Many thanks

1 hour ago, KodiFairy said:

Can someone please tell me which relay is it that this fault is relating to the one at the top of the image previously shown or the one at the bottom?

Many thanks

In my case, the bottom one. I drew a red box around it.

However, it still seems to come on randomly although not for as long.

It is going back to Skoda for them to repair as another garage said it is likely the control module meaning that the entire fan unit has to be replaced as it is integrated.

My quote from an independent :

Radiator fan (incl control module) £342.50 (£411 incl)

Labour £142.50 (£171 incl) - 1.5hrs @£95 p/h

£582 total

However, when it goes back to Skoda, I will fight like Mike Tyson as the car was under warranty when it went into them for repair and owing to their misdiagnosis is no longer covered. They will foot the bill or I will see them in small claims.

As an aside, the boot's "Virtual pedal" they were supposed to repair no longer works so they will have to repair that as well and refit the lower valance as they left off the screws holding it in place. The mind boggles.