P0650MIL Control Circuit/Open
- Generic OBD-II code · Powertrain
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The engine module switches the check engine light (MIL) through a low-side driver – or sends the command over CAN – and monitors the circuit: with the lamp off the line must carry supply voltage, with it on nearly 0 V. CARB requires the MIL to light for a bulb check at ignition on with the engine off (at least 15 s since model year 2005). GM's 2018–2025 modules use P0650 only for an open circuit (200 kΩ or more, above 11 V, 50 ms) and P263A/P263B for shorts to ground and voltage – stored without lighting the MIL, since a broken MIL cannot report itself; older GM diesels combine all faults in P0650. GM Europe's Saab 9-5 V6 checks only once the MIL has been commanded on and off. The engine runs normally, but emission faults go unseen and inspections fail if the lamp does not light at the bulb check.
- What you may notice
- MIL does not light at the bulb check
- MIL stays on (with a short or combined code)
- Code only visible with a scan tool, engine runs normally
- Failed emissions inspection
- Likely causes
- LikelyWire or connector between engine module and instrument cluster open or corroded
- LikelyMIL bulb burnt out or LED/instrument cluster faulty
- PossibleMIL supply in the cluster missing (fuse, ignition feed)
- PossibleShort in the circuit (at GM reported as P263A/P263B)
- RareOutput driver in the module faulty
- Inspection (ITP)
- Can matter for the ITP: it concerns the emissions system.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.