2013 Skoda Superb 2 Combi at approx 180,000km.
Worked fine yesterday.

Today, no start.

• Doors unlock fine.

• Upon opening the drivers door, the steering wheel did not make its normal unlock noise.

• Pressing start/stop button does not light up the dash or turn on any power.

• Pressing start/stop button with the keyfob, same as above.

• Battery fine, resting at 12.3V. Terminals clean.

I still need to:

• Inspect fuses inside and in the engine bay

I will:

• Order a Kessy button as apparently they can fail

Problem:

• Cannot scan with VCDS as the car won't turn on the power

Anyone seen this before? Found plenty of searches where the start/stop button starts to become unreliable but this one was all of a sudden. I'm hoping it's not the entry/auth module as I think you need a dealer to code that one.

Update:
- All fuses fine, including the ones in the engine bay fuse compartment

- Disconnected battery for 10 mins, reconnected, no change

- The hazard lights work fine, but the green indicators <-- and --> in the cluster do not illuminate with the hazards which is odd. Hoping it's not a cluster fail as that will be extremely expensive.

So to close this off it turned out it was water ingress to the CAN gateway.

Apparently when the sunroof drains block, water runs down the inside of the drivers side A pillar.

The CAN Gateway is apparently mounted connector side up so it's basically a bottle with an open top. The water runs down the cabling and fills up the plastic casing and corrodes the board.

At least it's a cheap-ish part to replace. The dealer stuck a second hand one in from an Octavia for now, which means everything works except the sunroof as the Octavia doesn't have LIN-bus sunroof. I'll get the appropriate one for the Superb from ebay and replace it myself.

Learnings:

Turns out the cluster-dead thing can be proven by just pressing the reset/set button on the cluster. Even without CAN it will wake up then.
You can't replace the start/stop button if you can't unlock the steering wheel, as you need to rotate it 90deg to expose the cover screws.

There doesn't appear to be a procedure to override/unlock the steering wheel if the module doesn't do it.

The trim around the gear stick requires a surprising amount of force to remove to expose the gearstick-unlock-yellow-button-thing.

VW master techs are worth their weight in platinum.

VW 'repair wires' are absurdly over priced.

You forgot: Keep your sunroof drains unblocked.

I've just bought brush/line for this purpose and will definitely be doing it now!

On 17/10/2025 at 20:36, persimmontom said:

You forgot: Keep your sunroof drains unblocked.

I've just bought brush/line for this purpose and will definitely be doing it now!

Yes before every winter now we do it.
The front ones I poke the innards of a bowden cable down from outside and then use the air compressor with the regulator wound down to minimum (~30psi).
The rear ones are easy, just drop down the rear headliner and can take the tubes off the barbs.

Got a brand new gateway from Ebay. Appeared to be third-shift product as it had the proper label but the Audi/VW logo was missing on the label. Device itself works fine.

Did have a minor shock where pretty much every module in the car showed in the gateway as 'module incorrectly coded'. Car started and ran fine. The root cause turned out to be the new gateway came OOB coded as left-hand drive and all my other modules are coded right-hand drive. Correcting it in the gateway made all the errors go away and it just worked.

Have stored the Octavia one in case something similar happens again.