Hello there!

 

I have a 54 plate Octavia Elegance 2.0TDi that is now refusing to start (been trying to work this out for a while now), it was an intermittent fault that used to go away after waiting  20mins or so but now it is persistent.

 

It also used to give sporadic ABS/ECS/Steering faults whilst driving along that would be cleared by restarting the car (ABS Pump/ECU has been out and been tested with no fault found).

 

The starting issue:

The engine will turn over and catch but within a second or 2 it cuts out, holding the key in the start position then just turns the starter over. A VCDS scan shows the immobiliser is kicking in and reporting faults for no comms with the instrument cluster. I also can not connect to ANY module other than the engine.

The instrument cluster also does not show any lights for indicators, headlights, main beam or any back lighting when side/dips are switched on. (Headlights and indicators do work)

 

VCDS-Lite Version: Release 1.2

Wednesday, 23 August 2017, 19:32:38.

 

 

Chassis Type: 1U - Skoda Octavia I

Scan: 01,02,03,08,15,16,17,19,22,29,35,36,37,39,46,56,76

 

-------------------------------------------------------------------------------

Address 01: Engine Labels: Redir Fail!

Controller: 03G 906 016 F

Component: R4 2,0L EDC G000SG 6201

Coding: 0000072

Shop #: WSC 73430

VCID: 263F759BD1FF

5 Faults Found:

18058 - Powertrain Data Bus: Missing Message from Instrument Cluster

P1650 - 000 - -

18107 - Shareware Version. To Decode all DTCs

P1699 - 000 - Please Register/Activate

18045 - Shareware Version. To Decode all DTCs

P1637 - 000 - Please Register/Activate

18043 - Powertrain Data Bus: Missing Message from A/C Controller

P1635 - 000 - -

17978 - Shareware Version. To Decode all DTCs

P1570 - 000 - Please Register/Activate

Readiness: N/A

 

End --------------------------------------------------------------------------------------------------

 

Things that have been checked (an Auto Sparky's verdict was to try a different CAN gateway:

 

• Connection on the back of the instrument cluster - was partially loose and has been reseated. Starting issue still present.
• Battery - have tried with a known good battery. Starting issue still continues.
• Fuel pump - pulled a line off, diesel pumped with ignition on
• BCM - no obvious loose connections - all connections remade
• ECU - no obvious damage or lose connections - connectors removed and reseated
• Fuses - Engine bay and dash fuse box fuses all checked twice. All fuses good.
• Relays - Engine bay and BCM relays all checked (actvation and resistance). All relays good.
• CAN gateway - connector removed and reseated. Starting issue continues and still can't see CAN gateway with VCDS (addr. 19).
• Different CAN gateway installed. Starting issue continues and still can't see CAN gateway with VCDS (addr. 19).
• CAN gateway connections checked. Tone on Diagnostic CAN lines from gateway to diagnostic connector.
• Battery tray removed. No obvious loose connections found.

 

• CAN gateway powered directly (12V) (pin 1&2) and all other pins connected to gateway connector. Multimeter shows approx 180mA being drawn by Gateway with ignition on but still no comms with CAN gateway with VCDS.
  • Trying to start the engine in this configuration gives some slightly different behaviour, the engine fails to start ion the same way (cuts out almost immediately) BUT VCDS scan shows only instrumetn cluster comms fault and immobiliser:

18058 - Powertrain Data Bus: Missing Message from Instrument Cluster

P1650 - 000 - -

17978 - Shareware Version. To Decode all DTCs

P1570 - 000 - Please Register/Activate

 

I'm now out of ideas other than to take the Engine Bay Fuse Box apart in the hunt for a loose connection.

 

 

 

FIXED: Turned out to be the +ve feed for the CAN gateway that was broken in the harness under the battery tray. repaired the broken cable and the vehicle now starts and drives as it should.