Replace interior light bulbs?

[Staffex]

Impedance is a meaningless term on a DC circuit. If the internal CANbus resistor has a value in the range suggested, a modern multimeter WILL accurately record the bulb's resistance. This is because the fixed resistor swamps anything due to the LEDs which are arranged in series/parallel strings and simply don't conduct at the voltage appearing across the test leads. If it wasn't so fiddly I'd have removed one of the bulbs to record its value here.
However, measuring a single white LED that was to hand gave a resistance of 10.2 Megs or infinity - depending which way round the Fluke's leads were connected; switching to diode test showed a forward drop of 1.78 Volts.

 

[salty]

Here's mine on me X Power. Red LED's brighter than the dull yellowish originals.
But not as bright as the White LEDs.
Just different, and I like that.

 

[gonzo]

Impedance is a meaningless term on a DC circuit. If the internal CANbus resistor has a value in the range suggested, a modern multimeter WILL accurately record the bulb's resistance. This is because the fixed resistor swamps anything due to the LEDs which are arranged in series/parallel strings and simply don't conduct at the voltage appearing across the test leads. If it wasn't so fiddly I'd have removed one of the bulbs to record its value here.
However, measuring a single white LED that was to hand gave a resistance of 10.2 Megs or infinity - depending which way round the Fluke's leads were connected; switching to diode test showed a forward drop of 1.78 Volts.

If measuring the resistance of an LED with the internal load resistor, I agree, a DMM will probably read that. And it will be the dominating term here.
But without knowing the bias voltage that a specific DMM uses for it's readings, the LED path may or may not influence the measurement.

But my point was, in this application, measuring resistances (of incandescent/LED/CANBUS LED)in isolation is not reliable or useful. Current drawn in an operating condition, for each device, is more helpful to us.

We still do not know if the controlling module even senses current drawn. And if so, what it's fault threshold is.
Connecting a power resistance decade box to the lamp holder would allow you to adjust the load and check if the unit ever reports an error and at what current level.
But I would suggest that MG will not have spent the extra time/cost on testing for bulb fail here. As it is not a safety critical case, as external lamps would be.
And even if they did, it must be at quite a low threshold, as the non error-preventing LED lamps I tried, work fine.