Wall Connector Ground Fault — Unable to Charge, Insufficient Grounding
The TESLA-CC_A002 (Tesla Wall Connector (charging equipment, not the vehicle)) EV fault code means: Wall Connector Ground Fault — Unable to Charge, Insufficient Grounding. This is a critical severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- professional
- Estimated cost
- Diagnosis by a licensed electrician. Cost depends entirely on what is found — a damaged connector or cable versus a wiring defect in the branch circuit are very different repairs, and only an inspection can tell them apart.
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Common Symptoms
- Touchscreen shows "Unable to charge — Insufficient grounding. Disconnect and retry or use different equipment"
- AC charging will not start on that Wall Connector
- The vehicle charges normally on a different connector or at a Supercharger
- The circuit breaker feeding the Wall Connector may trip
Probable Causes (Ranked by Likelihood)
- A ground fault: current is leaking through an unsafe path. Tesla names a line-to-ground or neutral-to-ground fault as the possibilities. This is a fault in the CHARGING EQUIPMENT AND ITS WIRING, not in the car. High
- Moisture, corrosion or damage in the Wall Connector, its cable, or the circuit feeding it. Medium
- An installation defect in the branch circuit — a bonded neutral and ground where they must be separate is the classic version. Medium
Frequently Asked Questions
What does CC_a002 mean?
Tesla's official text is "Unable to charge — Insufficient grounding", and the explanation given is a ground fault: current is leaking through an unsafe path, possibly a line-to-ground or neutral-to-ground fault.
Is CC_a002 a problem with my car?
No. CC_ alerts are Wall Connector faults. The car displays them because it is what shows you the message, but the fault is in the charging equipment and its wiring. Vehicle-side charge port alerts use the CP_ prefix instead.
Can I keep using the Wall Connector if CC_a002 keeps coming back?
No. A repeating ground fault means current is leaking through an unsafe path. Tesla directs you to consult an electrician or contact Tesla if the reset steps do not clear it. Charge elsewhere until it has been inspected.
Can I drive the car?
Yes. The fault is in the charging equipment, so the vehicle itself is unaffected — but you will need another way to charge until the connector is repaired.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
Treat this as an electrical safety fault, not an inconvenience. A ground fault means current is flowing somewhere it should not.
Tesla's first step: disconnect the Wall Connector from the vehicle and reconnect it.
If it persists: turn OFF the circuit breaker serving the Wall Connector, wait 10 seconds, turn it back ON, then reconnect to the vehicle.
If it still persists, Tesla says to consult your electrician or contact Tesla. Stop using that circuit until someone qualified has inspected it.
Confirm the fault follows the CONNECTOR, not the car, by charging elsewhere. If the vehicle charges fine on other equipment, the wall side is the problem.
Do not defeat, bypass or reset around a repeated ground fault. Refer to the installation guide for your specific Wall Connector.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- Tesla Model 3 Owner's ManualTroubleshooting Alerts (official Tesla alert text)
- Tesla Model Y Owner's ManualTroubleshooting Alerts (confirms the alert is documented across models)
Commonly Affected Vehicles
- Tesla Model 3
- Tesla Model Y
- Tesla Model S
- Tesla Model X
- Tesla Cybertruck
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