So I'm supposed to be driving 400+ miles tonight. Started the car this morning to be met by multiple lights, buzzers and a non functioning dash (apart from intermittent fuel gauge). Had been left facing down a slight hill for 3 days, no issues before then.

 

At the moment the car is drivable with oil pressure warning flashing, airbag light on, steering light flashing between orange & red, abs/traction lights on and no temp, revs or speed showing.

 

This is the Carista scan below, any one got any ideas? Wet ECU?

 

Instrument cluster:
01312 - Powertrain data-BUS

Central electronics:
01321 - Control Module for Airbags (J234)
01321 - Control Module for Airbags (J234)
01314 - Engine Control Module (ECM)
01309 - Power Steering Control Module (J500)

Body/convenience system:
01135 - Interior Monitoring Sensors
01321 - Control Module for Airbags (J234)
00625 - Vehicle Speed Signal (G22)

Driver's door:
01321 - Control Module for Airbags (J234)

Front passenger's door:
01321 - Control Module for Airbags (J234)

Heater & air conditioning:
00716 - Air recirculation Flap Positioning Motor (V113)
01316 - ABS Control Module
01314 - Engine Control Module (ECM)

Radio:
00625 - Vehicle Speed Signal (G22)

CAN network gateway:
01314 - Engine Control Module (ECM)
01316 - ABS Control Module
00778 - Steering Angle Sensor (G85)
01321 - Control Module for Airbags (J234)
01309 - Power Steering Control Module (J500)
01771 - Controller for shining width regulation (J431)
01312 - Powertrain data-BUS

 

Some may say points to a bad battery or bad earth. 

Bad earth / short somewhere sounds feasible.

 

AFAIK battery is good, it's has no issues starting after being stood in the cold etc. I don't have a meter here to test with unfortunately.

 

I'm going to drive it home and then go from there. It might fix itself if something dries out or die completely somewhere 7 hours from home.

So, did you make it.  Or still walking?  Seems like ECU moisture ingress seems  a decent likelihood likely with that many systems listed...

Made it

 

Set off with zero faults and driving fine, couple of hours in to journey it started raining and then the cruise control dropped out and the dash lit up and beeped.

 

Did the journey with various alarms (some very persistent) and with varying amounts of dash working.

 

This morning it's fine again apart from the air bag light as they never clear themselves.

 

So it's definitely water related I think. And it drives perfectly regardless of what lights showing.

 

The only thing is the steering feels different, I guess as it looses the steering sensor it usually does something to hold the steering straight ahead that doesn't work?

Hi Phil, 

I have similar issues with my mk3 octavia. I've been to two garages (one main dealer) and a few independent crafty guys and no one could sort it out so far. How did you sort out yours? 

Thanks! 

There is a big electrical connector on the steering rack / module right on the subframe, if water gets in this it can cause can bus communication issues which causes various other issues with bits also on the same canbus network.

 

I didn't have my under tray fitted and went through a very deep puddle and couple of miles later the dashboard went mad with all sorts of issues, speedo going beserk and whole host of faults when I plugged in the fault code reader.  After a few days of drying out all of the issues went away.  I did try to get the power steering connector off to apply some grease to give it a better seal but its really difficult to do so on axle stands and really needs to be on a lift or you need to drop the subframe.

 

Instead I sprayed the connector with some holts damp start which gives a bit of a lacquer seal to electrical connectors and have refitted the under tray and not had any issues since then.  

 

My power steering was going heavy and light by the way when the issue occured.