No dash lights. Car starts briefly then stops.

[nidgep]

Afternoon

 

Hoping for some advice.

Skoda Octavia Mk2 Scout TDi 2008.

Drove the car yesterday evening. Parked on the drive as usual.

Went to the car this afternoon and no dashboard lights.

Car will start briefly then stops.

Can hear the fuel pump just before turning the key.

Checked all fuses in the dash and under the bonnet and all good.

Disconnected the battery and left 10 minutes. Reconnected and still the same.

Attached photo of the LCD display before disconnecting the battery and photo of the fuse boxes.

 

Any further advice on what additional checks I can make to diagnose the issue?

 

Cheers

[nidgep]

Needed to add the under bonnet fuse box photo separately...

 

Also once the battery was reconnected the LCD display is now blank.

 

Edited 24 February by nidgep

[pikpilot]

What is the lowest battery voltage while attemping to start?

 

[xman]

Sounds as if a relay is not be turning on power to various modules. No idea which relay. There are apparently two levels of relays situated under the dash.

 

Engine starting briefly and shutting down usually because the immobiliser hasn't recognised the key. Probably in this case because the module needed is not receiving power.

 

Long shot, try the spare key.

[J.R.]

Immobiliser problem, try spare key as suggested.

[nidgep]

Thanks for the replies. Really appreciate the help.

 

As suggested, just tried the spare key and result was the same.

 

Ignition "on".

No instrument cluster lights.

Turn the key, car immediately starts and stops.

[Paws4Thot]

6 hours ago, nidgep said:

Thanks for the replies. Really appreciate the help.

 

As suggested, just tried the spare key and result was the same.

 

Ignition "on".

No instrument cluster lights.

Turn the key, car immediately starts and stops.

As others, I'm inclined to suspect an issue with the immobiliser. If you have access to another battery short of buying one, that would be worth a try first though.

[nidgep]

Thanks again for the replies.

Just been out to the car.

First thing was to check the initial battery voltage which read 12.21v (which seems low).

Attempted to start the car (started and stopped) and recorded the lowest cranking voltage which was 09.47v.

 

Battery is not that old (<2 years) but will put it on charge (CTEK) to see if it makes any difference or is that not worth persuing?

[nidgep]

Quick update.

No further forward I'm afraid.

Charged battery and refitted.

Removed lower dash panel to expose relays:

• Onboard power supply control unit (lower relays)
• Additional relay holder (upper relays)

Rechecked every fuse (with and without voltage applied) and all still seem to be fine with each having a good connection.

Attempted to check what I believe are the main relays hosted in the lower power supply control unit.

• B1 (KL15)
  • Terminal 15 voltage supply relay
• B4 (KL30)
  • Terminal 30 voltage supply relay
• B9 (KL75)
  • X contact relief relay

The upper relays

• D2
  • Terminal 50 voltage supply relay
  • Need to determine  what this powers.
  • The switched terminals of this relay didn't measure battery voltage (12.7v)
  • Instead measured < 1 volt.
    • To do check where the source of the supply voltage for this relay
    • Suspect B4 (KL30) relay

Each relay has been removed and tested (relay operates) and each can be felt to actuate when the ignition key is in the first position.
 

Additionally done a scan with VCDS which shows (perhaps unsurprisingly) malfunction in almost all modules (extract attached).
Main points from the scan are that comms with the immobiliser has failed.

25-Immobilizer -- Status: Cannot be reached 1100

Which I presume then leads on to the engine module reporting that the engine was prevented from starting by the immobiliser.

Any thoughts on where I can go from here?

 

005488 - Engine Start Blocked by Immobilizer 
               P1570 - 000 -  - MIL ON
             Freeze Frame:
                    Fault Status: 11110000
                    Fault Priority: 1
                    Fault Frequency: 1
                    Reset counter: 255
                    Mileage: 0 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 966 /min
                    Speed: 0.0 km/h
                    Load: 0.0 %
                    Voltage: 11.63 V
                    Bin. Bits: 11101100
                    Bin. Bits: 11000000
                    (no units): 33.0

Seems like the issue is power related or perhaps it's the instrument panel itself (given that the LCD was initially showing a strange pattern).
..or perhaps a poor connection or a bad earth?

I've attached a copy of the VCDS scan log if someone wouldn't mind casting a eye over it in case there is something to be gleaned from it.
There is mention of Terminal 30 low voltage.
 

VCDS-ScanLog-2024-02-27.txt

Edited 27 February by nidgep

[J.R.]

I didn't want to download the list but was VCDS able to communicate with any of the modules? Specifically instrument cluster and Canbus Gateway modules?

 

For the engine to start the instrument panel needs to recieve RFID data from the inductive reader around the ignition switch then communicate that to the ECU via canbus.

 

I think the instrument panel decides if the key is valid and tells the ECU to start the engine or not or maybe the ECU holds the authorised key date I cant recall which but if there is a failure in any module or the communications between them the result is cranking and firing for 1 second only.

 

Dry or fractured joints between the instrument binnacle connector and the circuit board can cause the problem, there are specialist repairers out there.

[nidgep]

Here's the summary from the VCDS log extract.

Basically failed to communicate with most modules.

01-Engine -- Status: Malfunction 0010
03-ABS Brakes -- Status: Malfunction 0010
04-Steering Angle -- Status: OK 0000
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: Malfunction 0010
15-Airbags -- Status: Malfunction 0010
16-Steering wheel -- Status: Malfunction 0010
17-Instruments -- Status: Cannot be reached 1100
19-CAN Gateway -- Status: Malfunction 0010
22-AWD -- Status: Malfunction 0010
25-Immobilizer -- Status: Cannot be reached 1100
42-Door Elect, Driver -- Status: Malfunction 0010
44-Steering Assist -- Status: Malfunction 0010
46-Central Conv. -- Status: Malfunction 1010
52-Door Elect, Pass. -- Status: Malfunction 0010
56-Radio -- Status: Malfunction 0010
62-Door, Rear Left -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
76-Park Assist -- Status: OK 0000

 

[nidgep]

22 minutes ago, J.R. said:

I didn't want to download the list but was VCDS able to communicate with any of the modules? Specifically instrument cluster and Canbus Gateway modules?

 

For the engine to start the instrument panel needs to recieve RFID data from the inductive reader around the ignition switch then communicate that to the ECU via canbus.

 

I think the instrument panel decides if the key is valid and tells the ECU to start the engine or not or maybe the ECU holds the authorised key date I cant recall which but if there is a failure in any module or the communications between them the result is cranking and firing for 1 second only.

 

Dry or fractured joints between the instrument binnacle connector and the circuit board can cause the problem, there are specialist repairers out there.

 

Would this prevent the dashboard from lighting up at all? It's completely blank.

Edited 27 February by nidgep

[xman]

I'd bet its one of those relays to blame. Just because you feel them click doesn't rule out a dry joint which is a common failure mode.

 

To start with, I'd turn the key to the ignition on position and start tapping each relay in turn while observing the dash for signs of life.

 

A schematic would help.

 

This may help

https://fuseandrelay.com/skoda/a5-octavia.html

 

Seems that B4 is the main supply relay

 

Have u checked the fuses in the engine compartment? F6 and R3

Edited 27 February by xman

[J.R.]

1 hour ago, nidgep said:

 

Would this prevent the dashboard from lighting up at all? It's completely blank.

A problem with the connector would definitely, whatever the cause if it does not light up the vehicle will be immobilised, I would start first with Xmans advice regarding the relays, I hope he is right as it will be simple to remedy.

 

Good luck!