What it means
The ECM detects a low 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 sends a signal used to monitor the charging connection's temperature. This code sets when that signal is lower than the control module's expected range, which can make temperature-based charging control unreliable.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- Connector pins corroded - high contact resistance
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 check sensor A's live reading for an implausibly low value compared with ambient temperature.
- Inspect the coupler sensor A connector for corrosion or poor pin contact, and examine its signal wire for a short to ground or damaged insulation.
- With the vehicle made safe according to its service information, check the sensor A signal circuit for a short to ground and test connector continuity.
- Test the sensor itself and its output against the manufacturer's specification to distinguish an internal short from a wiring fault.
- If the sensor and wiring pass, check the related input circuit and module readings using the vehicle's diagnostic information.
Common fixes
- Clean and reconnect corroded sensor A connector pins.
- Repair a signal wire shorted to ground or damaged connector.
- Replace coupler temperature sensor A if it fails its specification test.
- Repair a confirmed fault in the input circuit.
Can I keep driving?
Charging may be refused, slowed, or interrupted because sensor A is reporting an abnormally low signal. Avoid relying on public or unattended charging until the fault is checked; do not handle damaged high-voltage charging components.
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.