What it means
The control pilot charging switch A reports a stuck on 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 helps provide the vehicle’s charging handshake signal. This code sets when the module expects the switch to turn off but continues to detect it on, which can confuse charging authorization or interrupt the session.
Common causes
Most likely first.
- Charging switch A stuck in the on position
- Switch or switch circuit fault
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Save freeze-frame data and check charging live data to see whether switch A is reported on when the module expects it to be off.
- Inspect the switch A connector and harness for a short, trapped wire, corrosion, or a pin bridging adjacent terminals.
- Check whether operating and releasing the switch changes its reported state, using the manufacturer’s procedure.
- With the charging system safely isolated, test switch A for contacts stuck closed and inspect the circuit for a short that holds the signal on.
- Verify circuit continuity and connector condition against the manufacturer’s specification before considering a module fault.
Common fixes
- Clean and secure a corroded or poorly seated switch A connector.
- Repair wiring that is shorted or pinched and holding the signal on.
- Replace switch A if it remains on after release and the wiring is sound.
- Repair or replace the charging control module only after the switch and circuit test correctly.
Can I keep driving?
The vehicle may be driven if it otherwise behaves normally, but charging can be refused or interrupted. Avoid relying on a charge session until the switch state is corrected.
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.