What it means
The HV battery temperature sensor L reports a range/performance 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 checks whether its reading behaves plausibly compared with operating conditions and other battery data. This code sets when the L-channel reading is outside the expected range or responds inconsistently, even if the circuit is not simply open or shorted.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
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
- Record freeze-frame data with a compatible scan tool and note battery temperature, vehicle state, and the Sensor L reading when the fault occurred.
- Compare Sensor L with neighboring battery temperature readings after the vehicle has been sitting and during normal warm-up to identify a persistent mismatch.
- With the vehicle powered down according to its service information, inspect the L sensor's seating and nearby wiring for displacement, damage, or a loose connector.
- Have a qualified hybrid technician check the L-channel signal and circuit condition against the manufacturer's diagnostic procedure.
- If the circuit is sound, test Sensor L for calibration drift using the manufacturer's procedure and replace it if it is outside specification.
Common fixes
- Reseat Sensor L if it has shifted from its specified mounting position.
- Secure or repair a loose connector or damaged wiring on the L channel.
- Replace Sensor L if its temperature response is outside the manufacturer's specification.
- Verify that Sensor L tracks plausibly against the other battery temperature readings after repair.
Can I keep driving?
Reduced power or charging limits may occur while the module cannot trust Sensor L's temperature reading. Avoid demanding acceleration and unnecessary long trips, and stop safely if the vehicle displays a battery warning or enters a severe power restriction.
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.