What it means
The control module detects a fault 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 measures temperature at a monitored location in the hybrid or EV battery pack, and the control module uses its circuit signal to manage battery operation and cooling. This code sets when the module detects an electrical fault in sensor A's circuit, without specifying a particular signal direction or temperature mismatch.
Common causes
Most likely first.
- Failed temperature sensor
- Open or shorted wiring
- Loose or corroded connector
Symptoms
- Hybrid system warning light
How to diagnose it
- Save freeze-frame data and read battery temperature sensor A alongside other battery temperature readings for clues about the fault.
- Inspect the accessible sensor A harness and connector for loose terminals, corrosion, pin damage, or chafing.
- Check whether sensor A's reading changes plausibly as the pack warms or cools, using scan-tool live data.
- Following the manufacturer's safe procedure, test sensor A's circuit for an open or short and compare the sensor response with the manufacturer's specification.
- If the circuit and connector are sound, test or replace sensor A as indicated by the manufacturer's procedure.
Common fixes
- Reconnect or repair a loose or corroded sensor A connector.
- Repair an open or shorted sensor A wire.
- Replace battery temperature sensor A if it fails testing.
- Repair a control-module circuit fault if confirmed by testing.
Can I keep driving?
Have the fault checked promptly because the vehicle may not be able to rely on sensor A for battery temperature management and may restrict hybrid operation. Do not remove battery covers or handle high-voltage wiring.
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.