The control circuit of the belt-integrated starter/generator (BISG) belt tensioner reports a control circuit/open condition. Belt tension cannot be modulated for assist/regen modes.
Medium severity. Can I keep driving?If it starts normally you can keep driving, but avoid stopping anywhere you could not get help, because it might not restart.
Most likely causes
- Open in tensioner control wire
- Open tensioner actuator
- Pin pushed back out of connector body
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
What each character of P2CF9 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- C: Subsystem depends on the code range
- F9: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2CF9?
If it starts normally you can keep driving, but avoid stopping anywhere you could not get help, because it might not restart.
What causes code P2CF9?
The most common causes are: open in tensioner control wire; open tensioner actuator; pin pushed back out of connector body.
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.