Electrical Gremlins - 2002 XC 70

[beigg]

I'd went with Production 2 or Phase 2. Hope not Problematic 2

[mrbrian200]

CEL on lower right is controlled via direct connection to ECU, connector position 2. It will usually still light/function regardless of an otherwise dead DIM. It should be noted a simple logic circuit is incorporated (functionally a NC relay to the lamp) as the lamp lights when +signal from the ECU is *not present* on that wire/terminal (this is safeguard so that an open circuit/wire lights the CEL as opposed to disabling it).
Also note this lamp shares common ground through pin 4 with rest of DIM, suggesting the DIM ground is probably OK. I'm not sure where lamp power comes from for certain, though logic would dictate since MIL lights when +12v signal disappears from pin2 power for the lamp comes from pin4 (main +12v DIM power) suggesting that is probably ok too.

I agree with abscate you're at the point where you're unlikely to sort it without connecting the vehicle to a VIDA. Assuming the rebuilder (you didn't say who) thoroughly tested the DIM after repairing the board, if it's not lighting up that would indicate it's not communicating over CANBUS which could trace to any host of potential, seemingly unrelated causes.