2015 Subaru STI Check Engine Light with P000D and Multiple Codes

Most likely you’ve got a heat‑related wiring/connector issue on the passenger side, not four unrelated component failures. The codes and the smoke line up with something cooking in that harness area near the turbo/boost control and RH cam sensors. Runner‑up is oil contamination in the RH cam/AVCS area causing cam correlation and slow response, but the smoke under the harness makes me lean wiring first.

Most likely culprits

• Melted / chafed engine harness on RH side – P0245 (turbo wastegate solenoid low), P0341/P0346 (cam sensor/correlation) and P000D (slow cam response) can all pop if the shared harness by the turbo/AVCS gets cooked or rubbed through, especially under autocross heat/boost.
• Oil leak onto harness / cam sensor / AVCS solenoid – Oil in the connector or on the loom can cause intermittent cam signal and slow response (P000D, P0341, P0346) and smoke when it hits hot components.
• Boost control solenoid or RH cam sensor cooked – Less likely all at once, but a shorted solenoid or sensor can drag the circuit low (P0245) and generate localized heat/smoke.

The smoke under the cable bundle in your picture is the big clue: find the burn and you’ll find the fault.

How to narrow it down

1. Do a very careful visual/“smell” inspection in that red‑boxed area

   • Pull the intake duct out of the way if needed and open the loom where the smoke came from.
   • Look for: melted insulation, shiny copper, hardened/brittle loom, oil‑soaked tape, burnt smell.
   • If you find any melted/chafed wires, especially around the turbo, AVCS solenoids, cam sensors, or boost control solenoid, that’s your primary failure. Repair/replace harness section and re‑test.

2. Check oil level, condition, and for fresh oil leaks on RH head

   • Verify oil is at proper level and not fuel‑diluted or glittery.
   • Look around the RH valve cover, AVCS solenoids, cam sensors, and turbo feed/return lines for fresh oil tracks onto the harness or exhaust.
   • If you see oil on the harness where it smoked, clean it thoroughly, fix the leak (gasket/line/solenoid O‑ring), clear codes, and re‑test under load.

3. Scan all modules, pull freeze frame, and watch live data

   • Look at camshaft position (actual vs commanded), AVCS advance angles, and VVT solenoid duty for both banks.
   • See if the RH side (passenger) shows laggy or erratic advance compared to LH when you rev or do a quick road test.
   • For P0245, monitor boost control solenoid command vs feedback (if available) and check if the ECM is commanding it when the code sets.
   • If the codes are all on the same bank/side and correlate with heat/boost, that supports a localized harness/connector issue.

4. Electrical checks on the affected circuits

   Focus on the RH cam sensors and turbo boost control solenoid first, since they live right where you saw smoke.

   • Key off, unplug the boost control solenoid and both RH cam sensors (intake/exhaust).
   • Check resistance of each component against spec in service info. A dead short or open = bad part.
   • With connectors unplugged, key on, backprobe the harness side:
     • Verify 5V ref (if used), sensor supply, and ground at cam sensors.
     • Verify 12V feed and ground at boost control solenoid.
   • If you’re missing feed or ground on multiple components in that area, you’ve likely got a burned shared wire or splice in that loom.

5. Scope the RH cam sensor signals under heat/load

   • Scope both RH and LH cam sensors and the crank sensor.
   • Compare waveforms at idle and with a few controlled revs.
   • If the RH cam signal drops out, gets noisy, or shifts correlation only when hot, and you can reproduce it by wiggling the harness where it smoked, that’s harness/connector, not mechanical timing.

6. Check turbo/heat shielding and routing

   • Make sure all heat shields around the turbo and up‑pipe are present and tight.
   • Check that the harness in your photo hasn’t been rerouted closer to the turbo (aftermarket intake, previous work, etc.).
   • If the loom is sitting on a hot pipe or shield, you’ve found why it smoked and why you’re getting intermittent electrical codes.

7. Only after wiring checks out: consider internal AVCS/mechanical

   • If wiring and sensors test clean, but P000D/P0341/P0346 persist with clear cam correlation issues, then look at:
     • AVCS solenoid function (command vs response, possible sticking).
     • Oil supply to AVCS (sludge, restriction).
     • Mechanical timing (stretched chain/belt indexing is less likely on this platform at this age, but verify if there’s any history of timing work).

Possible parts (if needed)

• Engine harness section / repair pigtails for RH side near turbo/intake (if you find melted/chafed wires where it smoked).
• Turbo boost control solenoid (if P0245 persists and it tests shorted or heat‑damaged).
• RH camshaft position sensor(s) (if scope shows intermittent dropout and connectors/wiring are clean and solid).
• AVCS solenoid(s) on RH bank (only if commanded vs actual advance proves they’re sticking and wiring is verified good).
• Valve cover / AVCS/cam sensor seals (if you confirm oil leaking onto the harness/headers).

A few questions

1. Any mods in that area? Intake, turbo, EBCS, flex‑fuel, rotated kit, or harness rerouting that might have moved wiring closer to heat?
2. When it smoked, did you notice oil smell vs electrical/burnt plastic smell? That distinction matters.
3. Do the codes always come back only after hard runs/heat soak, or can you get them to set with a normal road test?

If you can, pull that loom open where the smoke came from and report what you see. That’s where I’d start if this was in my bay.