What it means
The HV battery temperature sensor L 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 L measures temperature at its assigned area of the high-voltage battery, and the hybrid control module uses that reading to manage battery power and charging. This code sets when the L-sensor signal changes erratically or drops in and out instead of remaining plausible.
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
- Use a compatible scan tool to save freeze-frame data and watch Sensor L live data for sudden jumps, dropouts, or brief implausible values.
- Compare the L reading with nearby battery temperature channels to determine whether the erratic behavior is limited to L.
- With the vehicle powered down according to its service information, inspect the L connector for incomplete seating, corrosion, damaged pins, or evidence of movement.
- Have a qualified hybrid technician check the L-sensor wiring and ground reference for intermittent contact while monitoring the circuit safely.
- If the connections and wiring are sound, test Sensor L using the manufacturer's procedure and replace the component confirmed to be erratic.
Common fixes
- Reseat and secure the Sensor L connector.
- Repair loose, corroded, or damaged L-channel connector terminals.
- Repair an intermittent Sensor L wire or ground connection.
- Replace Sensor L if testing confirms erratic sensor output.
Can I keep driving?
Intermittent Sensor L data can cause reduced power or charging restrictions without much warning. Avoid long trips and hard acceleration, and stop safely if the vehicle loses power or shows 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.