The ECM detects a range/performance fault on the cylinder head temperature sensor b. Reading cannot be used reliably for control.
Medium severity. Can I keep driving?If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
Most likely causes
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: easy
- It affects emissions.
What each character of P2C39 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- C: Subsystem depends on the code range
- 39: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2C39?
If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
What causes code P2C39?
The most common causes are: sensor characteristic drifted; sensor mounting displaced; sensor element aged beyond calibration window.
Related codes
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.