TESLA-CP_A079 moderate Tesla Charge Port (CP)

Charge Rate Reduced — Charge Port Latch May Be Frozen (AC Limited, No Supercharging)

The TESLA-CP_A079 (Tesla Charge Port (CP)) EV fault code means: Charge Rate Reduced — Charge Port Latch May Be Frozen (AC Limited, No Supercharging). This is a moderate severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
easy
Estimated cost
$0 — this is a cold-weather/seating condition resolved by reseating the cable or thawing the latch; no repair involved unless it persists in warm conditions.
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Common Symptoms

  • Alert on the touchscreen: "Charge rate reduced - Charge port may be frozen — Try using Defrost Car button in Mobile App"
  • AC charging limited to 16A; DC fast charging / Supercharging unavailable
  • Charge port light pulses amber during AC charging, solid amber when attempting to Supercharge
  • Appears in cold ambient temperatures

Probable Causes (Ranked by Likelihood)

  • The charge port latch can't secure the cable in the inlet and cold ambient temperature is detected — the latch may be frozen (Tesla's official description) Likely
  • The cable isn't fully inserted Possible
  • The manual release cable (in the trunk) has been pulled or is snagged, holding the latch open Possible
  • Debris, moisture, or a foreign object in the charge port inlet Possible

Frequently Asked Questions

What does CP_a079 mean on a Tesla?

Tesla's official meaning: the charge port latch can't secure the charge cable and cold temperature is detected — the latch may be frozen. Until it engages, AC charging is limited to 16A and Supercharging is unavailable. The port light pulses amber on AC, solid amber on a Supercharge attempt.

What's the difference between CP_a078 and CP_a079?

Both are frozen-latch alerts. CP_a078 means the latch can't RELEASE the cable (you can't unplug); CP_a079 means the latch can't SECURE the cable (charging is limited to 16A and Supercharging is blocked until it engages).

How do I fix CP_a079?

Re-seat the cable fully, check the trunk manual-release cable isn't pulled or snagged, clear any debris from the port, and if it's still limited run Defrost Car from the Tesla app for 30-45 minutes to thaw the latch. Slow (16A) AC charging still works in the meantime.

Mechanics Guide Step-by-step diagnosis

Step-by-Step Diagnostic Procedure

  1. Re-insert the charge cable fully. If charging starts and the port light pulses green, the cable wasn't fully seated — full-speed AC and Supercharging should be back.

  2. Check the charge port latch manual release cable (left side of the trunk): make sure it hasn't been pulled and nothing (cargo net, umbrella) is snagging its handle.

  3. Inspect the charge port inlet and connector for debris, moisture, or foreign objects; clear and dry, then retry.

  4. If it's still limited, the latch may be frozen: run Defrost Car from the Tesla mobile app for roughly 30-45 minutes (Tesla notes this works better than the in-car climate controls). Rear defrost can also help on vehicles with a charge port inlet heater.

  5. Per Tesla, limited AC charging (16A) remains available even while the alert is present — you're slow, not stranded.

Sources 4

This page is built from documented references. Verify against your own service info before repair work.

Commonly Affected Vehicles

  • Tesla Model 3
  • Tesla Model Y
  • Tesla Model S
  • Tesla Model X
  • Tesla Cybertruck

Related Codes

TESLA-CP_A078TESLA-CP_A054

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Tesla home All diesel codes Heavy-duty Guides

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