What it means
The control module detects a high signal in the circuit for hybrid/EV battery temperature sensor A.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery temperature sensor A reports temperature at a monitored point in the hybrid or EV battery pack. This code sets when the module sees a signal above its calibrated range, a condition that can result from an open signal circuit or a failed sensor.
Common causes
Most likely first.
- Open signal wire or circuit
- Failed sensor
- Wiring or connector fault
Symptoms
- Hybrid system warning light
How to diagnose it
- Record freeze-frame data and compare sensor A's live reading with other battery temperature sensors to identify an isolated high reading.
- Inspect the accessible sensor A connector and harness for an unplugged connector, broken wire, corrosion, or damaged terminals.
- Check whether sensor A's reading is fixed at a high limit rather than changing with battery temperature.
- Following the manufacturer's safe procedure, test the sensor A circuit for an open and check the sensor response to the manufacturer's specification.
- If the wiring and sensor pass, test the control-module input using the manufacturer's diagnostic procedure.
Common fixes
- Reconnect a disconnected sensor A connector.
- Repair an open or damaged sensor A signal wire.
- Replace sensor A if it fails testing.
- Repair a confirmed control-module input fault.
Can I keep driving?
Arrange diagnosis promptly because the module may not be able to determine the temperature at sensor A's battery location and may limit hybrid operation. Do not open the high-voltage battery enclosure.
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.