What it means
The control pilot charging switch A reports a circuit high condition. SAE J1772 charging signal handshake may be compromised.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Control pilot charging switch A provides a signal used in the charging handshake. The charging control module sets this code when the circuit signal is higher than expected, as can happen with a wire shorted to battery voltage or a switch that is not completing the circuit.
Common causes
Most likely first.
- Wire shorted to B+
- Switch open
- 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 review charging live data for switch A’s state and the conditions present when the high signal was detected.
- Inspect switch A’s connector and harness for corrosion, backed-out pins, damaged insulation, or contact with a voltage supply.
- Check whether switch A changes state in live data when operated, following the vehicle’s service information.
- With the charging system safely isolated as specified by the manufacturer, test the switch and circuit for an open or short to voltage.
- Verify connector pin fit and circuit continuity, and compare results with the manufacturer’s specification before suspecting the charging control module.
Common fixes
- Clean and secure corroded or poorly seated connector pins.
- Repair wiring shorted to voltage or damaged in the harness.
- Replace a switch A that tests open or fails to change state.
- Repair or replace the charging control module only after circuit tests rule out the switch and wiring.
Can I keep driving?
Driving may be possible if the vehicle has no other warnings, but charging can be unavailable or interrupted. Plan for limited range and do not keep using a connector or harness that is damaged or overheats.
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.