P2CFB: Belt Integrated Starter Generator Belt Tensioner Control Circuit High

The control circuit of the belt-integrated starter/generator (BISG) belt tensioner reports a control circuit high 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

Control wire shorted to B+
Open tensioner actuator
Connector pins corroded - high contact resistance

What to check, in order

Start with the simplest. You can tick off each step.

Check the battery voltage
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Try another key, if you have one
Check the fuses and the starter relay
Check the wiring and the signal to the starter motor

Good to know

Repair difficulty: medium
It can trigger limp mode.

What each character of P2CFB means

P: Powertrain: engine and transmission
2: Generic code: same on every make
C: Subsystem depends on the code range
FB: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2CFB?

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 P2CFB?

The most common causes are: control wire shorted to B+; open tensioner actuator; connector pins corroded - high contact resistance.

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.