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Subaru P0455

CONTINUED ON THE NEXT PAGE Special Edition TechTIPS Page 10 of 14 SUMMARY OF EVAP LEAK DIAGNOSIS (CONTINUED) This is an example of a completed self-test, with “P0456” set after bei

DriveUnknown. The verified record lists safe-to-drive status as unknown.
ChargeUnknown. The verified record lists safe-to-charge status as unknown.
ServiceContact a Subaru dealer or qualified Subaru service provider for diagnosis, especially if P0455 remains present after testing or is accompanied by other DTCs.
Confidence95%

Quick answer

Verified evidence identifies P0455 in a Subaru TechTIPS document as a DTC that may be displayed after an EVAP self-test. The supplied evidence does not establish a complete code definition, a specific fault cause, or an owner repair.

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

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1. What does P0455 mean?

Verified evidence identifies P0455 in a Subaru TechTIPS document as a DTC that may be displayed after an EVAP self-test. The supplied evidence does not establish a complete code definition, a specific fault cause, or an owner repair.

2. Technical explanation

The cited NHTSA-posted Subaru TechTIPS document includes an example of a completed EVAP self-test with P0455 set. The same document also shows examples with “No DTC,” P0456, and P2404 after the self-test. It notes that an SSM4 software issue could affect verification of whether DTCs are set and states that this would be corrected by a future software update. The supplied evidence does not establish that P0455 itself is caused by that software issue.

3. What system is affected?

EVAP leak diagnosis / EVAP self-test, based on the Subaru TechTIPS source.

4. How serious is this code?

Unknown. The verified record lists severity as unknown.

5. Symptoms you may notice

  • A completed EVAP self-test may show P0455, according to the cited Subaru TechTIPS example.
  • No vehicle symptoms are established by the supplied verified evidence.

6. Possible causes

  • Not yet established by verified evidence.

7. Can I still drive the vehicle?

Unknown. The verified record lists safe-to-drive status as unknown.

8. Can I charge the vehicle?

Unknown. The verified record lists safe-to-charge status as unknown.

9. What you can safely do

  • Record the exact DTC and the conditions under which it was retrieved.
  • Have a Subaru service provider evaluate the vehicle using applicable Subaru diagnostic information.
  • Do not attempt high-voltage system repair based on this code.

10. Step-by-step troubleshooting

  1. The supplied evidence confirms P0455 can appear after an EVAP self-test.
  2. The supplied evidence does not provide a verified step-by-step diagnostic procedure for P0455.
  3. A Subaru service provider can determine whether relevant scan-tool software updates or diagnostic procedures apply.

11. When to contact service

Contact a Subaru dealer or qualified Subaru service provider for diagnosis, especially if P0455 remains present after testing or is accompanied by other DTCs.

12. What the service center may check

  • Confirm the DTC with Subaru-compatible diagnostic equipment.
  • Review EVAP self-test results.
  • Check whether applicable SSM4 software updates are relevant; the cited document states an SSM4 software issue would be corrected by a future update, but does not establish that it causes P0455.

13. Possible repair or resolution

  • Not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • NHTSA Manufacturer Communication PDF 10219476: Subaru Tech Tips, published August 12, 2022. It includes EVAP self-test examples showing No DTC, P0455, P0456, and P2404, and references an SSM4 software issue to be corrected by a future update.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official source: NHTSA-posted Subaru Tech Tips, Manufacturer Communication 10219476 (https://static.nhtsa.gov/odi/tsbs/2022/MC-10219476-0001.pdf).

19. Frequently asked questions

What does the supplied evidence verify about P0455?

It verifies that P0455 is shown in a Subaru TechTIPS example after a completed EVAP self-test.

Does the evidence confirm the cause of P0455?

No. A specific cause is not yet established by verified evidence.

Is it safe to drive or charge with P0455?

The supplied verified record marks both safe-to-drive and safe-to-charge status as unknown.

20. Sources & verification

ReferenceVerified
Subaru P0455: CONTINUED ON THE NEXT PAGE Special Edition TechTIPS Page… | EV Diagnostics