What it means
The HV battery temperature sensor P reports a circuit intermittent/erratic fault. Cell-group temperature monitoring impaired on this channel.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Sensor P measures a section of the high-voltage battery, and the battery control module expects its temperature signal to change smoothly. This code sets when Sensor P’s signal is intermittent or erratic, which can result from an incompletely seated connector, a noisy ground reference, or contacts that open with vibration.
Common causes
Most likely first.
- Connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Review freeze-frame data and Sensor P live data for abrupt jumps or dropouts compared with the other battery temperature sensors.
- Following the manufacturer’s high-voltage shutdown procedure, inspect Sensor P’s connector for incomplete seating, corrosion, loose pins, or evidence it moves in its housing.
- Inspect Sensor P’s harness and ground-reference connection for chafing, looseness, or strain that could create an intermittent contact.
- While observing live data, check whether gentle movement of the accessible low-voltage harness makes Sensor P’s reading fluctuate.
- Test the ground reference, signal continuity, and terminal retention using the manufacturer’s wiring information; replace Sensor P only if these connections are sound.
Common fixes
- Fully seat and secure Sensor P’s connector.
- Clean or repair loose or corroded terminals and restore the ground-reference connection.
- Repair harness damage or wiring that loses contact under vibration.
- Replace Sensor P if the intermittent signal remains with sound wiring and connections.
Can I keep driving?
An unstable Sensor P reading can trigger unpredictable limits on power or charging, so keep trips short if the warning or reduced-power mode is present. Stop safely if the vehicle loses power or displays a high-voltage battery warning.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.