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Subaru P04AE

test. On turbocharged vehicles, after performing the ELCM self-test, without turning the key off, perform an all DTC scan to verify there are no DTC’s set. This is a problem with t

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact a Subaru dealer or qualified service professional if diagnosis is needed. The supplied evidence does not establish consumer-level repair steps.
Confidence95%

Quick answer

P04AE is referenced in a Subaru TechTIPS communication about EVAP leak diagnosis. For turbocharged vehicles, Subaru states that P04AE will not set after an ELCM self-test because of an SSM4 software issue; without turning the key off, perform an all-DTC scan to confirm no DTCs are set.

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 P04AE mean?

P04AE is referenced in a Subaru TechTIPS communication about EVAP leak diagnosis. For turbocharged vehicles, Subaru states that P04AE will not set after an ELCM self-test because of an SSM4 software issue; without turning the key off, perform an all-DTC scan to confirm no DTCs are set.

2. Technical explanation

The verified source describes P04AE only in the context of EVAP leak diagnosis and the ELCM self-test. It states that turbocharged vehicles will not set P04AE after the self-test due to an SSM4 software problem, planned for correction in a future update. The supplied evidence does not establish a full fault definition for P04AE.

3. What system is affected?

EVAP leak diagnosis / ELCM self-test context. A more specific affected component or system is not yet established by verified evidence.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

Not yet established by verified evidence.

6. Possible causes

  • On turbocharged vehicles, the verified Subaru communication identifies an SSM4 software issue that prevents P04AE from setting after the ELCM self-test.

7. Can I still drive the vehicle?

Not yet established by verified evidence.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • If a qualified technician is performing the ELCM self-test on a turbocharged vehicle, Subaru instructs them not to turn the key off before performing an all-DTC scan.
  • Use a complete DTC scan to verify whether any DTCs are present after the self-test.

10. Step-by-step troubleshooting

  1. Perform the ELCM self-test as applicable.
  2. For turbocharged vehicles, do not turn the key off after the test.
  3. Perform an all-DTC scan and verify that no DTCs are set.

11. When to contact service

Contact a Subaru dealer or qualified service professional if diagnosis is needed. The supplied evidence does not establish consumer-level repair steps.

12. What the service center may check

  • Perform the ELCM self-test.
  • On turbocharged vehicles, perform an all-DTC scan without turning the key off after the self-test.
  • Verify whether any DTCs are set.

13. Possible repair or resolution

  • The verified communication says the SSM4 software issue was to be corrected with a future software update. Availability, applicability, and repair outcome are 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: https://static.nhtsa.gov/odi/tsbs/2022/MC-10219476-0001.pdf
  • NHTSA Manufacturer Communication PDF 11024859, Subaru Tech Tips, published October 28, 2025: https://static.nhtsa.gov/odi/tsbs/2025/MC-11024859-0001.pdf
  • NHTSA Manufacturer Communication PDF 11024863, Subaru Tech Tips, published October 28, 2025: https://static.nhtsa.gov/odi/tsbs/2025/MC-11024863-0001.pdf
  • NHTSA Manufacturer Communication PDF 11036794, Article Locator, published August 5, 2026: https://static.nhtsa.gov/odi/tsbs/2026/MC-11036794-0001.pdf

16. Recall information

No recall relationship is established by verified evidence.

17. Official manufacturer information

Verified evidence includes Subaru manufacturer communications published through NHTSA. No recall information was supplied.

19. Frequently asked questions

What does the supplied Subaru evidence say about P04AE?

It says turbocharged vehicles will not set P04AE after an ELCM self-test because of an SSM4 software problem.

What should be checked after an ELCM self-test on a turbocharged vehicle?

Without turning the key off, perform an all-DTC scan and verify that no DTCs are set.

Does the evidence establish that P04AE applies to a Subaru Solterra?

The supplied applicability data lists Solterra, but the cited TechTIPS excerpt specifically discusses turbocharged vehicles. Direct Solterra applicability of the described diagnostic issue is not yet established by verified evidence.

20. Sources & verification

ReferenceVerified
Subaru P04AE: test. On turbocharged vehicles, after performing the… | EV Diagnostics