Originally Posted by Ripper
According to my circuit diagram the leds are powered from fuse 10 through the ignition switch and the ECU switches them on by providing the ground connection internally. First thing to do is check for voltage on the red/blue wire by placing a multimeter across the red/blue wire and the battery -ve with the ignition on.
I said pretty much all that in post #2!
Except you have the Fuse ID incorrect however - definitely Fuse 8 - Fuse 10 is on the output to Parking Lights, not the input to the Red/Blue circuit
Current flow goes:
Battery -> Fuse 11 -> Brown Wire to key-switch -> Out on Blue/Yellow from Key-Switch -> Fuse 8 -> Red/Blue Wire -> Instrument Back Lights & LEDs
Red/Blue also then feeds as a secondary branch back into another
pole of the key-switch and out through Red/Orange wire and then through Fuse 10 out to Parking Lights
If the panel back-lights are on then the red/blue circuit is good eliminating fuses/key switch (and also if the park lights are on, the Red/Blue circuit must
be hot in order to power those too)
Extremely unlikely to be ECM error - most likely connector issue I would expect, at the LED interconnect itself.