P26C9Chassis Control Module 2 Requested MIL Illumination
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P26C9 is the message slot for a second chassis control module: if module 2 detects an emission-related fault, it can ask the engine module to switch on the check engine lamp, and the engine module records this request as P26C9. No manufacturer documents this code in public. The mechanism is known from its partner P26C8, which GM monitors in its 2018 engine and hybrid tables continuously from three seconds after power-up as Type A without its own lamp request. CARB's OBD rule requires that emission-relevant faults of other control units reach the driver through the MIL, which is why such forwarding codes exist. P26C9 says nothing about the actual defect – only reading the fault memory of chassis module 2 shows what lies behind it.
- What you may notice
- Check engine lamp on
- Codes stored in a chassis module in addition to the engine module
- Likely causes
- LikelyEmission-related fault stored in chassis control module 2
- RareIncorrect configuration or software after module replacement
- RareLow voltage or network fault corrupting the request message
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.