Dashboard like a Christmas tree help!!!

[kaluharu]

I have a 2017 2.0lt diesel auto Leon, I drove the car on Saturday with no issues. Went to get in it yesterday when I was presented with just about every warning going and it wouldn't allow me to turn the car on. Left it for the day come back and used the spare key, no warnings car turned over just fine. Put the other key in and all of the faults returned and wouldn't let me turn it over. Left it again and the spare key works just fine, what's going on??

 

[nd-photo.nl]

Check your battery and replace if needed. This is the season that weak batteries are exposed due to declining temperature

 

[tracktoy]

Do you have a scan tool to see what error codes the car is giving you.

When I get that number of issues you are seeing would be down to speed sensor failure but neither that or the battery makes sense if the car works fine on the second key.

 

[Mr Pig]

It's possibly just a coincidence that it works with the other key. Maybe the car warming up a little between tries allows it to start. I'd say that if it's on the original battery it's probably a good idea to swap it. The battery is seven years old and they typically don't last much longer than that.

 

[kaluharu]

So had it at the garage yesterday replaced the key in the battery it then works fine. Had it out today for a journey from a to b, fine b to c fine c to d fine then wouldn't start again. Thankfully I was outside of a garage put another new battery in the key and hey presto the car started again.

Could this all be down to a dodgy key?

 

[ViperSlider]

Are both your keys genuine or is one/both aftermarket?

 

[kaluharu]

Are both your keys genuine or is one/both aftermarket?

Unsure how to tell but both came with the car when I bought it? I had the car just over a year and no issues until now

 

[kaluharu]

Oh and have a new battery on the car that was put on in February.

 

[nd-photo.nl]

Ah ok, thanks for clarifying

 

[mty12345]

You need to scan the car and get a list of fault codes. Could be some sort of CANBUS issue or low voltage codes, but without fault codes it's just guessing.

No way a key could cause it, just coincidence. The only thing the battery in the key does is operate the central locking/alarm. Any garage that doesn't know that is just gonna waste your time and money, and probably just start throwing random parts at it. They should have plugged it into a diagnostics machine, not been messing about with your key.

 

[Walone]

I'm wondering if the IMMO transmitter in the key is giving an intermittent fault and perhaps changing the battery sorts it temporarily?

 

[ViperSlider]

Unsure how to tell but both came with the car when I bought it? I had the car just over a year and no issues until now

The keys should be identical, down to the stamp marks on the key blade (HAA on one side and possibly VSY on the other).

If they are then the issue could be in your clocks as that is where the immo is located. Ideally you want the car inspected by a good diagnostic garage with brand specific equipment (ODIS ideally or VCDS as a minimum) so they can see whats stored and whats happening.

This is all guess work of course, it could be almost anything causing it. "Lights on the dash and car not starting" is about a vague as it gets lol

I've replaced a number of clocks on a wide range of VW Group cars, including Seats as they do die.

 

[cairus]

Just a guess, I am speculating that the ignition contact block is broken or the coil for the Key

 

[johnnygal]

I had something very similar earlier this year. I drove to work, parked up and when I came to go home, I unlocked the car and got an error about door control module. When I tried to start the car, there was no attempt from the starter motor and every warning you can possibly think of came on the dash.

AA tried a new (car) battery but no different.

(The short story) - it was traced to corroded wires at the connectors in the passenger footwell. A lot of the wiring harness had to be replaced to fix.

The thought was that the washer pipe that runs along here to the rear washer had leaked at some point and caused it. I am the second owner, so maybe this happened to the previous owner and was fixed but didn't dry out the connectors.

At some point during the saga, I connected with Carista, and the one that jumped out to me was "
CAN network gateway:
65795 - Medium Speed CAN Communication Bus: (-) shorted to Bus (+)
".

This kind of confirmed to me it was a wiring short somewhere.

Also, bit like yours, sometimes (usually if you tried to start the car straight away) it would start the engine. I would still have numerous errors coming up after a few seconds but the engine would run.

Amyway, thought I would post as it may help you. Like others have said, get a OBD reader that can interrogate all the ECUs and see what it shows.

Good luck!

Addition: I see someone suggested ignition block - this was one of the first thing the first garage tried - with no luck.

Please keep us posted on how you get on, I would be very interested to hear what the cause is, once it is identified.

 

[kaluharu]

Hi all so it's been to the garage again, no faults detected, no codes, nothing! At a loss now and without a code we can't go replacing things willy nilly as itll be a stab in the dark at best. Urgh.

Edit: it's started doing it on the spare key now too

 

[Mr Pig]

Hi all so it's been to the garage again, no faults detected, no codes, nothing! At a loss now and without a code we can't go replacing things willy nilly as itll be a stab in the dark at best. Urgh.

This is the worst kind of fault to have on a car :0(

My approach would be to work through it logically. What is t he history? What has happened to the car in the past that might have resulted in damaged wiring, plugs or components? Aftermarket accessories fitted? Dashcam, lights, cheapo gizmos? Impact damage? Water damage? Is the new battery the correct one for the car? Was it correctly coded to the car?

The odds are that some event in the past has caused this fault. It could be a random chafed cable but it's not very likely. Where did you get the new battery?

 

[johnnygal]

Hi all so it's been to the garage again, no faults detected, no codes, nothing! At a loss now and without a code we can't go replacing things willy nilly as itll be a stab in the dark at best. Urgh.

Edit: it's started doing it on the spare key now too

Very strange, given all the faults listed on the screen in your initial post. Are you sure they read off all the computers, and not just the engine, which is what basic OBD scanners do? Personally think the key is a red herring - just that it's intermittent. Sometimes it's better if it stops altogether, will be easier to trace a 'hard' fault.

 

[Mr Pig]

Personally think the key is a red herring - just that it's intermittent.

I agree. I can't see any way a bad key could cause these symptoms.

 

[ViperSlider]

Grab a video of the fault occurring.

For the car to have no fault codes stored, including historical ones, that seems unlikely. Especially with failed starting and warning lights on the dash. As above, unless the equipment used can DTC scan all modules in the car then it may not see any stored outside of the ECU but even then, I'd expect to see some in the ECU for something like no comms with BCM or Immo or engine start blocked or just something. To have nothing is even stranger than the fault itself.

It does smell a little like instrument cluster fault but without a fault code pointing in that direction or viewing the live data as the fault is occurring then it's still crystal ball time.

 

[Mr Pig]

Grab a video of the fault occurring.

For the car to have no fault codes stored, including historical ones, that seems unlikely.

Very. Modern cars have so many sensors and systems they collect fault codes for fun. I don't think I've ever scanned one of our cars without seeing a code or two, even when there is nothing wrong.