What it means
The control pilot charging switch B reports a intermittent/erratic condition. SAE J1772 charging signal handshake may be compromised.
At a glance
- Usually lights the check-engine light
How it works
Control pilot charging switch B supplies a monitored signal used in the charging handshake. P2DD2 sets when the module sees that signal fluctuate or behave inconsistently, often because a connection or ground loses contact intermittently.
Common causes
Most likely first.
- Connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Review freeze-frame and live switch B data to identify whether the erratic reading occurs during plug-in, charging, or movement of the vehicle or cable.
- Inspect switch B's connector for a loose latch, backed-out pins, corrosion, or signs of movement.
- Check the harness and ground reference for chafing or looseness, gently moving the wiring while monitoring the signal for dropouts.
- Test switch B circuit continuity and ground stability while flexing the harness, using the manufacturer's procedure.
- If the external circuit remains stable, monitor the controller input during a charging attempt to isolate an internal fault.
Common fixes
- Reseat and secure the switch B connector.
- Clean or repair a poor ground or corroded terminal.
- Repair chafed or intermittently open switch B wiring.
- Replace switch B if its output remains erratic with sound wiring.
Can I keep driving?
Driving is generally unaffected, but charging can start and stop unpredictably, so do not rely on a single successful charge as proof the problem is resolved. Stop using the charging equipment if a connector is damaged or becomes unusually hot.
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.