Instrument Cluster digital lights not working!

[Alrahi]

Originally Posted by wpoll

I agree it's unlikely - the vehicle's comms bus system and circuity is pretty robust!

And yeah, clearly there is some limited form of comms working but if there was no other action that could cause the failure (beyond simply unplugging the looms) then what else could it be?

Total back-light lamp supply failure in the cluster? Not all of the lower display is back-it LCD, the warning indicator lamps are LED - but I guess they might use the same supply?

TIS indicates that the warning lamps are mostly ground-switched via the various modules (SRS, ABS etc.) but the signals (indicators) are a K-bus message from the LCM. Maybe even these use the same +ve supply.

If fuses F1, F43 and F45 are good and power is being supplied to the cluster connector X1175, pins 20, 21 and 22 then deeper checks might be needed...

Hopefully no electronics were fried!
I will check the voltage supply to the fuses and pins also and hope I can get some closure.