I have owned my 2011 Mk2 Scout from new. It has recently developed a strange electrical fault: Main beam o/side comes on briefly for 5 seconds then goes out (n/side working fine) Warning light indicating 'bulb failure' appears on maxidot computer, but the bulb is not at fault, for as explained it will illuminate momentarily.

So there must be a 'short circuit' occurring somewhere? Has anyone else ever experienced similar in any Mk2 Octavia? Mine has the Xenon upgrade, but that only applies to dipped beam, not main, so is probably irrelevant.

Any advice gratefully received. And does anyone know where to obtain the applicable wiring diagram as my local garage is struggling to?

Many thanks

The chances are the bulb is on its way out but still working, albeit with a resistance above the upper value the Body Control Module thinks is acceptable.  This would cause the bulb to light for a few seconds until the BCM then shuts it off due to a high resistance, interpreting this as a blown bulb.

 

Have you tried replacing the bulb at all?

Or swap the bulbs over to other side.to test them.

Yes, replaced bulb with new (makes no difference) - and also swapped over entire headlight unit to test by plugging in n/side unit to o/side connector which produces same malfunction where main beam activates briefly before cutting out - which confirms that problem must be in wiring (somewhere) to o/side?