P2D9B
Starter/Generator Phase U Current Circuit Intermittent/Erratic
The current measurement on starter/generator phase U drops out or jumps intermittently. Loose connector or vibration-sensitive sensor.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Sensor connector not seatedCommon
- Harness chafing intermittently shorts the wirePossible
- Connector with intermittent contact under vibrationLess likely
Parts involved
- Starter Generator Phase U Current Sensor
- Wiring Harness
- Hybrid Control Module
P2D9B is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.