What it means
The proximity detection circuit B (SAE J1772 PD signal) reports a intermittent/erratic condition. Charging cable plug detection is impaired.
At a glance
- Usually lights the check-engine light
How it works
The J1772 proximity-detection (PD) circuit B helps the vehicle recognize the charging plug at the inlet. The control module sets this code when the circuit B signal changes erratically or intermittently, so plug detection can drop in and out.
Common causes
Most likely first.
- Charge inlet contacts dirty
- Wiring fault
- Connector with intermittent contact under vibration
Symptoms
- Check-engine or charging-system warning light
- Charging may start or stop intermittently
How to diagnose it
- Review freeze-frame data and ask whether the warning or charge interruption occurs over bumps, during plug movement, or with one cable.
- Inspect the charge inlet contacts for dirt, moisture, corrosion, looseness, or signs of heat damage.
- Check circuit B wiring and connectors for a loose terminal, damaged insulation, or a harness that moves against nearby parts.
- Watch the scan-tool PD circuit B status while gently moving the accessible harness and connector, without disturbing a live charging connection.
- If the fault remains, test circuit B continuity while flexing the disconnected harness and compare results with the manufacturer's specification.
Common fixes
- Clean and dry dirty charge-inlet contacts using an approved method.
- Repair loose or damaged circuit B wiring and connector terminals.
- Replace a charge inlet or connector with an intermittent contact if cleaning and wiring repair do not restore a stable signal.
Can I keep driving?
Charging can stop unexpectedly if plug detection drops out, so avoid relying on this vehicle for a trip that requires a full charge. Stop using a cable or inlet that feels loose, becomes hot, or shows visible 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.