What it means
The ECM detects a range/performance fault on the battery charger coupler temperature sensor a circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The battery charger coupler temperature sensor A reports temperature at the charging connection so the control module can assess charging conditions. This code sets when the signal is present but falls outside the expected range or does not behave as expected, making coupler temperature unreliable for charging control.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Record freeze-frame data and compare sensor A's live temperature reading with ambient temperature before charging and with its response during charging, if charging can be safely started.
- Inspect the coupler sensor A and its mounting for displacement, damage, or contamination that could affect how it senses temperature.
- Check the sensor A connector and wiring for loose connections, corrosion, or damage that could distort the signal.
- Compare sensor A's output and temperature response with the manufacturer's specification to identify a drifting or aged sensor.
- If the sensor and its connections check out, follow the vehicle's diagnostic information to check the related input circuit and control-module interpretation.
Common fixes
- Reseat and secure the coupler sensor A mounting.
- Clean and reconnect the sensor A connector, repairing damaged wiring as needed.
- Replace the out-of-calibration coupler temperature sensor A.
- Repair a confirmed fault in the input circuit.
Can I keep driving?
Charging may be reduced, interrupted, or unavailable because the vehicle cannot rely on coupler temperature sensor A. Avoid depending on normal charging until the fault is diagnosed, and stop charging if the coupler becomes unusually hot or shows damage.
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.