Hello,

 

Does anyone have (or know a good place to find) a comprehensive wiring diagram for the CAN bus on a MK1 Octavia?

 

Thanks,

I don't the mk1 uses CAN 

Hello,

 

Thanks for the reply.  The Mk1 uses CAN quite extensively, but doesn't expose it directly to the diag port as far as I'm aware.

 

I'm particularly interested in the wiring path, and any tests which might be possible, on the Powertrain bus.  Does anyone have any workshop diagrams etc for this? Edit: especially between SAS, ABS and dash (gateway).

 

Thanks again,

Hello,

 

The Mk1 uses CAN quite extensively, but doesn't expose it directly to the diag port as far as I'm aware.

 

 

 

 

Ah got you, I know VCDS doesn't pick it up as CAN.

 

Sorry got no info for you though.

You don't say what car it is - year/engine code/gearbox code.

The powertrain CAN-bus is limited to

ECU

ABS

Cluster Insert

Haldex controller (if fitted)

Automatic gearbox controller (if fitted)

Wiring is twisted pair.

CANL is orange/brown

CANH is orange/black

Thanks, that's helpful - so I need to trace the or/br and or/bl pair.

 

I've got a communication problem with the steering angle sensor.  This error is being picked up by both the gateway, which I believe is in the dash, and the ABS controller.  From what I can work out, this means that there must be either a fault with the sensor, or the wiring as far as fas as the bulkhead - as if there was a wiring problem in the engine bay it shouldn't stop the gateway from communicating with the sensor.

 

Do you know the route from the sensor itself to the dash?  Or where there are any junctions?

 

Mk1 Octavia 4x4, so all of the above nodes except gearbox.

 

 

 

You don't say what car it is - year/engine code/gearbox code.

The powertrain CAN-bus is limited to

ECU
ABS
Cluster Insert
Haldex controller (if fitted)
Automatic gearbox controller (if fitted)

Wiring is twisted pair.
CANL is orange/brown
CANH is orange/black

An hour on erWin should be enough to get the wiring info you need.

The steering angle sensor has a 6-pin connector and may connect direct to CAN-bus or connect at the ABS controller (may still connect to the CAN-bus pins - can't remember). I'd check the power first.

pin 1 - earth

pin 2 - CANL

pin 3 - CANH

pin 4 - +ve from fuse 15

pin 5 - +ve switched from fuse 9

pin 6 - N/C

RWB: Thank you once more.  I'll try and expose the wires from pins 4 and 5 to check for bat+ when the sensor is playing up.  It's weirdly intermittent - it can work perfectly (engine running or not) for a few minutes, updating the values in measuring block 4 (I think) of the ABS controller before suddenly cutting out - even with the car perfectly still.  I'd like to hope that the designers took advantage of the bus topology to connect to somewhere near the sensor.

 

DGW: I've no idea what that means (just off to Google erWin in a minute ) but it's nice to see a "familiar" name.  Quite a lot has changed here in the last few years!

Fuse 9 also feeds the ESP/TCS switch so I'd check that feed first (it's either black/grey or grey/black - can't remember which way round it is).

I'm not sure that'll help very much.  The switch works when the SAS is OK, but as soon as it stops communicating, the switch has no effect because ESP is disabled.  Unless you're saying it might be easier for me to test the wire from there, rather than taking the steering wheel off?

You can register for erWin using the first link below then, when you want access, you can pay for one hour of use, one day, or longer, depending on how deep your pockets are.

https://erwin.skoda-auto.cz/erwin/showCustomerRegistration.do

More info on erWin is in this second link.

https://erwin.skoda-auto.cz/erwin/showInfoTour.do

Well thanks to everyone for your help, here's a little update.  I took all the various bit of trim off to expose the SAS ready for a bit of diagnosing as soon as the ESP light came on.

 

Well that was a week and 500 miles ago!  Since then there hasn't been a single comms error, compared with it happening within a few minutes each time the ignition was cycled before.

 

I don't know whether I re-seated a connection, or whether disconnecting the battery (as part of the airbag disconnection procedure) reset something - I'll just have to keep an eye on it...

 

Finding about about erWin is amazing though!