Chevrolet P0401
The technician should follow SI diagnostics. If no cause for the concern is found or during diagno
Quick answer
For the supplied Chevrolet applicability, P0401 appears in GM bulletin PIP5684/PIP5684A/B/C as one of many possible current or history DTCs. The bulletin directs technicians to follow SI diagnostics. It identifies a charge-air-cooler/induction-system leak as a possible cause of the listed concern, but does not establish that this is the cause of P0401 in every vehicle.
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 P0401 mean?
For the supplied Chevrolet applicability, P0401 appears in GM bulletin PIP5684/PIP5684A/B/C as one of many possible current or history DTCs. The bulletin directs technicians to follow SI diagnostics. It identifies a charge-air-cooler/induction-system leak as a possible cause of the listed concern, but does not establish that this is the cause of P0401 in every vehicle.
2. Technical explanation
The verified diagnostic record names P0401 with the truncated manufacturer wording: “The technician should follow SI diagnostics. If no cause for the concern is found or during diagno.” Official NHTSA-posted GM communications PIP5684 through PIP5684C list P0401 among numerous DTCs that may be present as current or history codes. Those communications state that the MIL may be illuminated and that reduced engine power may occur intermittently. They state that the concern may be due to a leak in the charge air cooler/induction systems and direct the technician to follow SI diagnostics. The evidence does not establish a complete P0401 definition, a specific failed component, or a universal repair.
3. What system is affected?
Not yet established by verified evidence. The cited bulletin discusses the charge air cooler/induction systems as a possible area of concern.
4. How serious is this code?
Unknown. The supplied diagnostic record does not establish severity.
5. Symptoms you may notice
- The MIL may be illuminated.
- Intermittent reduced engine power may be reported.
6. Possible causes
- A leak in the charge air cooler/induction systems may be a cause of the concern described in GM bulletin PIP5684 and revisions. This is not established as the cause of P0401 in every vehicle.
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
- Arrange diagnosis using the manufacturer’s SI diagnostic procedure.
- Do not assume that a charge-air-cooler or induction-system leak is confirmed solely because P0401 is stored.
10. Step-by-step troubleshooting
- A qualified technician should follow SI diagnostics, as directed by GM bulletin PIP5684 and its revisions.
- If no cause is found through SI diagnostics, the supplied evidence does not provide further complete diagnostic instructions.
11. When to contact service
Service is appropriate if the MIL is illuminated or reduced engine power is present. The supplied evidence directs technicians to use SI diagnostics.
12. What the service center may check
- Retrieve and assess current and history DTCs.
- Follow the applicable GM SI diagnostic procedure.
- Evaluate the charge air cooler/induction systems only as supported by SI diagnostics; the bulletin identifies leaks there as a possible cause of the broader concern.
13. Possible repair or resolution
- Not yet established by verified evidence. The cited bulletin does not provide a confirmed P0401-specific repair in the supplied evidence.
14. Affected vehicles
- Chevrolet Bolt EV · 2011–2018 · US
- Chevrolet Spark · 2011–2018 · US
- Chevrolet Volt · 2011–2018 · US
15. Related TSBs / service bulletins
- GM PIP5684, published via NHTSA on 2019-10-22: lists P0401 among possible current/history codes; a charge-air-cooler/induction-system leak may cause the concern; follow SI diagnostics. https://static.nhtsa.gov/odi/tsbs/2019/MC-10167455-9999.pdf
- GM PIP5684A, published via NHTSA on 2020-05-05: same verified P0401 listing and SI-diagnostics direction. https://static.nhtsa.gov/odi/tsbs/2020/MC-10176300-9999.pdf
- GM PIP5684B, published via NHTSA on 2020-07-13: same verified P0401 listing and SI-diagnostics direction. https://static.nhtsa.gov/odi/tsbs/2020/MC-10178370-9999.pdf
- GM PIP5684C, published via NHTSA on 2020-10-22: same verified P0401 listing and SI-diagnostics direction. https://static.nhtsa.gov/odi/tsbs/2020/MC-10182564-9999.pdf
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified sources are NHTSA-posted GM manufacturer communications PIP5684, PIP5684A, PIP5684B, and PIP5684C. The supplied data associates this record with Chevrolet Bolt EV, Spark, and Volt, model years 2011–2018, US region. The supplied evidence does not establish exact vehicle, powertrain, or bulletin applicability beyond that data.
- NHTSA: NHTSA Manufacturer Communication PDF 10167455: PIP5684 · official_tsb
- NHTSA: NHTSA Manufacturer Communication PDF 10176300: PIP5684A · official_tsb
- NHTSA: NHTSA Manufacturer Communication PDF 10178370: PIP5684B · official_tsb
- NHTSA: NHTSA Manufacturer Communication PDF 10182564: PIP5684C · official_tsb
19. Frequently asked questions
Does P0401 confirm an induction-system leak?
No. The bulletin says a charge-air-cooler/induction-system leak may cause the broader concern, but it does not establish that such a leak is confirmed whenever P0401 is present.
What does GM direct the technician to do?
Follow SI diagnostics.
Can P0401 be accompanied by reduced power?
The cited bulletin says customers may report intermittent reduced engine power when the listed concern is present. It does not establish that every P0401 event will produce reduced power.