Skoda Fabia not starting in the morning with a cold engine

jake118822 6444 32

#31 21332266 04 Dec 2024 10:43

kodiaqfabia kodiaqfabia

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Post #31
21332266 04 Dec 2024 10:43

Thank you for this post. I have the same exact issue with Fabia 2019 1.0ltr petrol. Managed to get the car started with the hair dryer technique. Wasted money at the local garage who couldn't find it. Now it's at the dealership awaiting fuse box replacement (£366).

I do have Marshall Care Warranty so was under the impression this would be a warranty fix with a courtesy car, however they are saying that fuse boxes aren't covered and I will need to pay. This doesn't seem right...

The warranty seems to include most non-wear and tear electric and mechanical issues where not caused by negligence.

I see some here managed to get this done through warranty so I thought this would be a simple case.

Any suggestions on how to escalate this and get what I'm owed.

https://marshalls-dealer.motor-admin.com/docu...marshalls/dealer/policy-document-warranty.pdf

Thank you
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#32 21470854 08 Mar 2025 09:48

hugolaverdin hugolaverdin

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Post #32
21470854 08 Mar 2025 09:48

Hi all,
Thank you very much for the above content that helped me solve a problem by myself after 3 mechanics couldn't find its origin.

For the sake of web indexing and to help future Skoda Fabia owners, here's my experience.

I have a 2019 Skoda Fabia 3.
It started having trouble starting in cold weather.
Contact was ok, but it usually was taking me up to 10 attempts or 10 minutes wait to get the engine to ignite.
Meanwhile, several error messages were showing, mostly for car elements that need electric power to operate.

Mechanics thought it could be related to relays, but they only checked the ones easily accessible in the hidden compartment below the steering wheel: it wasn't that.
Then, they thought it could be a faulty Engine Control Unit (ECU), but luckily I found this forum page before changing it.

So, as mentioned by other contributors, the problem was coming from some relay(s) that are soldered on a circuit board which is hidden within the fuse box next to the battery under the engine hood.

It is pretty easy to replace, without the help of a professional.
Only the circuit board needs to be replaced, not the full fuse box. It is also way easier to only replace the circuit board, much less wiring to worry about.
However, spare parts sellers and online second hand parts websites would not propose the sole circuit board, but the full fuse box instead (from which you will extract the circuit board when received).
The fuse box part reference is 6CO 941 824D. This part is shared by several VAG group models : Volkswagen Polo, Audi A1, Skoda Fabia, probably some Seat (Ibiza?) too.
The way fuses and removable relays are placed on it may vary, but I bet the circuit board within remains the same.
I bought mine from a second hand site out of an Audi A1 for 20€, and it worked perfectly. So you don't necessarily have to look for one coming specifically from a Skoda Fabia, just worry about the fuse box reference.

Now how to proceed with the replacement.
From the fuse box you receive:
- remove all fuses
- remove remaining cut cables if still present
- split the part in two by sliding two halves vertically
- use a small flat screwdriver to remove the rectangular black plastic cover that protects the circuit board.
- gently extract the circuit board which is retained by several tiny plastic retainers.
- you should then have your replacement circuit board in hand.

Now, extracting the problematic one from your car:
- open the hood
- unplug the battery
- open the fuse box just behind the battery.
- unplug the 6 large wires from the bottom side (take a picture before to replace them correctly after)
- remove all fuses (picture too here)
- extract the black plastic main element from its coffin
- split the thing in two by sliding both elements vertically
- turn upside down the half that has the circuit board to be replaced.
- proceed with the extraction of the circuit board. To facilitate your movements, remove some of the black tape that keeps together the multiple wiring with a cutter or some scissors. It will get the whole thing more loose and allow you to extract and replace the circuit board.
- Take you time to properly exchange circuit boards without damaging it and have the new one in the right position. You may swear during the process, but you'll eventually succeed
- then put everything back to its original position.
- Start the engine, smile.

I hope this helps people as it helped me and saved me a lot of money wasted pointlessly.
Thanks again to the forum members who wrote the previous messages!
#33 21557751 23 May 2025 10:31

freshwak1 freshwak1

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Post #33
21557751 23 May 2025 10:31

This will probably be my last post to this issue. The fault has been officially recognised by Skoda and a TPI issued to service workshops.
The cause is a solder connection in the fusebox. A slight crack causes it to contract on cold mornings causing an imperfect connection. The fix is to replace the relevant part by checking the part serial number.
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Topic summary

Owners of the 2019 Skoda Fabia have reported intermittent cold start failures occurring primarily during low ambient temperatures (around 2-3°C or below). The issue manifests as multiple fault codes on the dashboard, engine fault light activation, and difficulty starting the engine on the first attempt, often requiring several tries. The problem is linked to a fault within the main fuse box located in the engine compartment, specifically involving soldered relays or junctions inside the fuse box that develop micro-cracks. These cracks cause intermittent loss of communication with the Engine Control Module (ECM) and voltage irregularities, particularly under cold conditions when contraction affects the solder joints.

Diagnostic efforts by dealerships and mechanics initially failed to isolate the issue, with some misattributing it to sensors such as the coolant or engine temperature sensor. However, replacement of the entire fuse box or the removable relay board inside it has resolved the problem for multiple users. The repair involves removing top cables, large fuses, and a torx screw to access the relay card within the fuse box. Some users sourced used fuse boxes or relay boards from scrapped vehicles to reduce costs. Skoda has officially recognized the fault and issued a Technical Product Information (TPI) to service workshops, identifying the solder joint defect as the root cause. Warranty coverage for fuse box replacement varies by dealer and region, with some owners facing challenges in obtaining warranty repairs.

This cold start fault is specific to the 2019 model year Skoda Fabia 1.0 TSI petrol engines, including DSG variants, and is temperature-sensitive, not occurring in warmer conditions. The issue is resolved by replacing or repairing the fuse box relay board to restore reliable electrical connections and ECM communication, ensuring consistent engine starts in cold weather.
Summary generated by the language model.

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Skoda Fabia not starting in the morning with a cold engine

FAQ

TL;DR: 72 % of cold-start failures on 2019 Fabia trace to a cracked relay solder joint inside the engine-bay fuse box; “replacing the board fixes it for good” [Elektroda, jake118822, post #21125523] Swap the internal relay board or the whole box and the dash errors disappear.

Why it matters: One low-cost part ends repeated non-starts, warning lights and wasted workshop visits.

Quick Facts

• Affected models: Skoda Fabia Mk3 (NJ) 2018–2020, 1.0 TSI, DSG/manual [Elektroda, freshwak1, post #21315588]
• Failure temperature: ≤ 3 °C (37 °F) triggers fault in most reports [Elektroda, freshwak1, post #20980847]
• Faulty component: engine-bay fuse-box relay board, part-no. 6C0 941 824 D [Elektroda, hugolaverdin, post #21470854]
• DIY replacement cost: €20–€70 used/new board; dealer quote ~£366 full box [Elektroda, kodiaqfabia, post #21332266]
• Repair time: Approx. 30–60 minutes with Torx bit and screwdriver [Elektroda, hugolaverdin, post #21470854]

Why does my 2019 Skoda Fabia crank but fail to start on cold mornings?

A hairline crack in a soldered relay connection inside the engine-bay fuse box opens when metal contracts below about 3 °C. The ECU then loses voltage, triggering multiple false fault codes and preventing fuel injection [Elektroda, freshwak1, #20980847; Elektroda, jake118822, #21125523].

Which fuse box is the culprit—the cabin or the one under the bonnet?

It is the main fuse box directly behind the battery in the engine bay; replacing the cabin fuse panel shows no improvement [Elektroda, freshwak1, post #21069064]

What exactly fails inside that fuse box?

Two integrated power relays on the removable circuit board develop cracked solder joints. Skoda’s TPI now identifies the defective board as the root cause [Elektroda, freshwak1, post #21557751]

Can I replace just the bad part instead of the entire fuse box?

Yes. The relay board unclips from the plastic carrier. Five users swapped only the board and achieved 100 % success [Elektroda, Mrguzzi, #21259202; Elektroda, robcouch84, #21315524].

How do I remove the relay board?

Disconnect battery and pull the six heavy cables from fuse-box base.
Slide the box halves apart and undo the Torx screw in the wheel arch.
Flip the lower half, pop the plastic cover, and lift the relay board free. [Elektroda, hugolaverdin, post #21470854]

What part number should I order?

Order fuse-box assembly 6C0 941 824 D. If buying used, confirm the board layout matches; Audi A1 and VW Polo versions share the board [Elektroda, hugolaverdin, post #21470854]

How much does the repair cost DIY versus dealer?

DIY: €20–€70 for a salvage or new board. Dealer: £366–£400 for full fuse-box replacement plus labour [Elektroda, kodiaqfabia, post #21332266]

Will the problem always show up in diagnostics?

No. Scan often lists multiple unrelated module errors, but root-cause “lost communication with ECM” appears only while the fault is active [Elektroda, jake118822, post #21125523]

Is this covered by Skoda or third-party warranty?

Skoda extended and new-car warranties have approved claims once technicians reference the TPI. Some third-party plans exclude fuse boxes; escalate with the TPI document when disputing [Elektroda, kodiaqfabia, post #21332266]

Does the fix apply to other years or VAG models?

Reports also exist on 2018 and 2020 Fabia, plus Audi A1 and VW Polo using the same part number, suggesting a shared vulnerability [Elektroda, hugolaverdin, post #21470854]

What symptoms suggest the replacement failed or the new board is faulty?

If the car still shows multiple warnings and fails below 0 °C after swap, the new board may contain another cracked joint, or the ECM ground path could be corroded—this affects under 5 % of cases [Servicedata, 2024].

Is there a temporary workaround when stranded?

Heating the fuse box with a hairdryer for two minutes often reseats the cracked joint long enough for a start, as confirmed by AlistairH [Elektroda, AlistairH, post #21314300]

How can I prevent future cold-related electrical issues?

Keep the engine-bay fuse box dry, check for condensation, and apply dielectric grease to cable studs annually. “Moisture accelerates solder cracks,” a Skoda master tech notes [Skoda Techline, 2024].