What it means
The control pilot charging switch A reports a circuit low 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 is part of the signal path used during the vehicle’s charging handshake. The charging control module monitors its circuit and sets this code when the signal is lower than expected, which can prevent the vehicle and charger from agreeing to charge.
Common causes
Most likely first.
- Wire shorted to ground
- Switch shorted
- 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
- Use a scan tool to save freeze-frame data and check charging-system live data for switch A’s reported state when the fault occurs.
- Inspect switch A’s connector and nearby wiring for corrosion, damage, moisture, or a wire contacting ground.
- Check whether the switch changes state in live data when operated, if the vehicle’s service information provides a safe test procedure.
- With the system made safe according to the manufacturer’s procedure, test switch A and its circuit for a short to ground.
- Check connector pin condition and circuit continuity, then compare measurements with the manufacturer’s specification before considering a control module fault.
Common fixes
- Clean and secure corroded or loose switch A connector pins.
- Repair wiring shorted to ground or damaged insulation.
- Replace a faulty control pilot charging switch A.
- Repair the circuit or replace the charging control module only if testing confirms the fault.
Can I keep driving?
You can generally drive if the vehicle otherwise operates normally, but charging may fail or stop, so avoid relying on it for a trip that requires charging. Stop charging if the connector or wiring shows damage or becomes unusually warm.
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.