EV Diagnostics
Verified EV diagnostic knowledge page

Tesla CP_a151

Charge port error detected - Service is required AC charging may not function / OK to Supercharge

Common search variants: CPa151 · CP-a151 · CP a151 · Search ignores case and common separators.

DriveNot yet established by verified evidence. The supplied alert addresses charging capability and states that Supercharging is OK; it does not provide a verified driving-status determination.
ChargeAC charging may not function while CP_a151 remains present. The alert specifically states that Supercharging is OK.
ServiceTesla service is required according to the CP_a151 alert.
Confidence95%

Quick answer

CP_a151 is a Tesla charge-port alert. Verified owner-manual evidence states that the charge port requires service because it cannot establish a valid control-pilot signal to communicate effectively with some AC charging equipment and power sources. AC charging may not function while the alert is present; the alert states that Supercharging is OK.

This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.

Video guides

Watch Videos

Relevant videos play here without leaving this diagnostic page.

No sufficiently relevant embeddable video has been accepted for this diagnostic yet.

Videos are supporting material and never override OEM or regulator evidence.

1. What does CP_a151 mean?

CP_a151 is a Tesla charge-port alert. Verified owner-manual evidence states that the charge port requires service because it cannot establish a valid control-pilot signal to communicate effectively with some AC charging equipment and power sources. AC charging may not function while the alert is present; the alert states that Supercharging is OK.

2. Technical explanation

The verified documentation identifies a control-pilot communication problem at the vehicle charge port. The control-pilot signal is used for communication with AC charging equipment and power sources. Because a valid signal cannot be established, some AC charging equipment may not work while CP_a151 remains displayed. The supplied evidence does not establish a specific failed part or an underlying physical cause.

3. What system is affected?

Charge port and its AC charging control-pilot communication function.

4. How serious is this code?

The database severity value is unknown. However, the verified alert explicitly says that service is required and that AC charging may not function.

5. Symptoms you may notice

  • CP_a151: “Charge port error detected - Service is required AC charging may not function / OK to Supercharge.”
  • The charge port is unable to establish a valid control-pilot signal.
  • The vehicle may be unable to communicate effectively with some AC charging equipment and power sources.
  • AC charging may not function while the alert remains present.
  • The alert indicates that Supercharging is OK.

6. Possible causes

  • Verified cause description: the charge port cannot establish a valid control-pilot signal for effective communication with some AC charging equipment and power sources.
  • A specific component failure or physical root cause is not yet established by verified evidence.

7. Can I still drive the vehicle?

Not yet established by verified evidence. The supplied alert addresses charging capability and states that Supercharging is OK; it does not provide a verified driving-status determination.

8. Can I charge the vehicle?

AC charging may not function while CP_a151 remains present. The alert specifically states that Supercharging is OK.

9. What you can safely do

  • Arrange service for the charge port, as directed by the alert.
  • If charging is needed, the verified alert indicates that Supercharging is OK.
  • Do not attempt high-voltage or charge-port repair yourself.

10. Step-by-step troubleshooting

  1. The supplied verified evidence does not establish owner-performed troubleshooting steps beyond using a Tesla Supercharger or Destination Charging location as referenced in the owner-manual material.
  2. Do not treat a successful or unsuccessful charging attempt as confirmation of a specific failed component; a root cause is not established by the supplied evidence.

11. When to contact service

Tesla service is required according to the CP_a151 alert.

12. What the service center may check

  • Confirm the CP_a151 alert and assess the charge port’s ability to establish a valid control-pilot signal with AC charging equipment.
  • Determine why the charge port cannot communicate effectively with some AC charging equipment and power sources. Specific diagnostic procedures are not yet established by verified evidence.

13. Possible repair or resolution

  • Charge-port service is required according to the verified alert.
  • The specific repair or replacement that resolves CP_a151 is not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Verified NHTSA manufacturer communications include Tesla owner-manual material documenting CP_a151, including NHTSA document MC-10250484-9999 (published December 1, 2023): https://static.nhtsa.gov/odi/tsbs/2023/MC-10250484-9999.pdf
  • Additional supplied NHTSA manufacturer communications repeat the same owner-manual alert text. No model-specific repair bulletin or repair procedure is established by the supplied evidence.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official NHTSA-hosted Tesla owner-manual documentation describes CP_a151 as a charge-port error requiring service, with possible loss of AC charging and Supercharging indicated as OK. Example source: https://static.nhtsa.gov/odi/tsbs/2023/MC-10250484-9999.pdf. Supplied applicability records list US Tesla Model 3, Model S, Model X, and Model Y entries across overlapping model-year ranges from 2012 through 2024; exact applicability for a specific vehicle is not established by this evidence alone.

19. Frequently asked questions

What does Tesla alert CP_a151 mean?

It means the charge port requires service because it cannot establish a valid control-pilot signal and cannot communicate effectively with some AC charging equipment and power sources.

Will AC charging work with CP_a151?

AC charging may not function while the alert remains present.

Can I Supercharge with CP_a151?

Yes. The verified alert states that Supercharging is OK.

Is service required?

Yes. The alert explicitly says that service is required.

What part needs to be replaced?

Not yet established by verified evidence.

Is it safe to drive?

Not yet established by verified evidence. The supplied documentation does not provide a driving-status determination.

20. Sources & verification

Accepted ResearchVerified
Show all 58 verified sources
Tesla CP_a151: Charge port error detected - Service is required AC… | EV Diagnostics