What it means
The HV battery temperature sensor L reports a circuit 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 Sensor L circuit has an electrical fault, so the module cannot reliably monitor that battery area.
Common causes
Most likely first.
- Failed temperature sensor
- Open, shorted, or damaged wiring
- Loose or corroded connector
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 check whether the Sensor L reading is missing, implausible, or fixed.
- Compare Sensor L with other battery temperature readings to confirm the fault is isolated to the L channel.
- With the vehicle powered down according to its service information, inspect the L-sensor connector and accessible wiring for looseness, corrosion, cuts, or pin damage.
- Have a qualified hybrid technician test the Sensor L circuit for an open or short and verify its connections against the wiring diagram.
- If the wiring and connector pass, test Sensor L using the manufacturer's procedure and replace it if it fails.
Common fixes
- Secure a loose Sensor L connector.
- Repair damaged Sensor L wiring or corroded connector terminals.
- Replace Sensor L if circuit checks confirm the sensor has failed.
- Clear the code and confirm the L-channel reading is plausible after repair.
Can I keep driving?
The vehicle may restrict power or charging because it cannot reliably monitor the battery area served by Sensor L. Limit driving to what is necessary and avoid hard acceleration or extended trips; stop safely if power drops sharply or a high-voltage battery warning appears.
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.