P2DE7Cold Start Engine Coolant Bypass Valve C Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- California requires a fault found while the cold-start warm-up strategy runs to be stored apart from the same fault found later. P2DE7 is that cold-start counterpart of P26BB for coolant valve C. GM's 2025 ECM tables (25OBDG03B) set it when the valve's measured angle is more than 12° off its target after the target has settled, or when the valve moves slower than calibrated, during 4 of 5 seconds. Extra conditions are a low-flow coolant mode (also during auto-stop), active catalyst warm-up, closed-loop position control without soft opening, soft closing or anti-stick routine, and outlet coolant above −20 °C. Type B, MIL after two trips. A slow valve can let coolant circulate too early, so engine and catalyst heat up later. Position-sensor faults (P23C3 ff.) block the test.
- What you may notice
- Check engine light on (after two trips)
- Engine and cabin heater warm up more slowly
- Usually no change in driveability
- Likely causes
- LikelyRotary valve sluggish from deposits or worn seals
- PossibleValve actuator motor or gearing weak
- PossiblePosition sensor reading drifting without a circuit fault
- RareEngine control software needing an update
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.