Chevrolet P015B
The technician should follow SI diag
Quick answer
For Chevrolet vehicles in the supplied applicability data, DTC P015B is titled “The technician should follow SI diag.” Official GM communications list P015B among codes that may be present with an illuminated MIL and intermittent reduced engine power; they state the concern may be due to a leak in the charge-air-cooler/induction system and direct technicians to follow SI diagnostics.
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1. What does P015B mean?
For Chevrolet vehicles in the supplied applicability data, DTC P015B is titled “The technician should follow SI diag.” Official GM communications list P015B among codes that may be present with an illuminated MIL and intermittent reduced engine power; they state the concern may be due to a leak in the charge-air-cooler/induction system and direct technicians to follow SI diagnostics.
2. Technical explanation
The verified diagnostic record provides no expanded code definition beyond “The technician should follow SI diag.” The official communications do not establish that every P015B occurrence has the same cause. They identify a charge-air-cooler/induction-system leak as a possible cause for the described condition and instruct technicians to use SI diagnostic procedures.
3. What system is affected?
Not yet established by verified evidence. The cited communications identify the charge-air-cooler/induction system as a possible area of concern.
4. How serious is this code?
Unknown. The supplied diagnostic record lists severity as unknown.
5. Symptoms you may notice
- MIL illuminated.
- Intermittent reduced engine power may be reported.
6. Possible causes
- A leak in the charge-air-cooler/induction system may be the cause of the concern described in GM PIP5684 and its revisions.
7. Can I still drive the vehicle?
Unknown. The supplied diagnostic record lists safe-to-drive status as unknown. Because reduced engine power may occur, have the vehicle evaluated if the MIL is illuminated or power is reduced.
8. Can I charge the vehicle?
Unknown. The supplied diagnostic record lists safe-to-charge status as unknown.
9. What you can safely do
- Record whether the MIL is illuminated and whether reduced engine power occurs intermittently.
- Arrange professional diagnosis using the applicable GM Service Information (SI) procedures.
- Do not attempt high-voltage system repairs based on this code.
10. Step-by-step troubleshooting
- A qualified technician should follow the applicable GM SI diagnostic procedure, as directed by the official communications.
- The official communications identify inspection and diagnosis of possible charge-air-cooler/induction-system leaks as relevant to the described concern.
11. When to contact service
Service is appropriate when P015B is present, particularly if the MIL is illuminated or intermittent reduced engine power occurs. The supplied record does not establish an emergency or stop-driving instruction.
12. What the service center may check
- Retrieve and assess current and history DTCs.
- Follow the applicable GM SI diagnostic procedure for the vehicle and code.
- Diagnose for a possible leak in the charge-air-cooler/induction system, consistent with GM PIP5684 communications.
13. Possible repair or resolution
- Not yet established by verified evidence. The official communications direct the technician to follow SI diagnostics; they do not provide a verified universal 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 October 22, 2019; NHTSA manufacturer communication MC-10167455.
- GM PIP5684A, published May 5, 2020; NHTSA manufacturer communication MC-10176300.
- GM PIP5684B, published July 13, 2020; NHTSA manufacturer communication MC-10178370.
- GM PIP5684C, published October 22, 2020; NHTSA manufacturer communication MC-10182564. These communications list P015B among possible current or history codes, describe MIL illumination and possible intermittent reduced engine power, identify a possible charge-air-cooler/induction leak, and direct use of SI diagnostics.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified applicability supplied: Chevrolet Bolt EV, Spark, and Volt, model years 2011–2018, United States. The supplied evidence does not establish applicability by individual powertrain, trim, or VIN. Official NHTSA-hosted GM communication: https://static.nhtsa.gov/odi/tsbs/2020/MC-10182564-9999.pdf
- 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
What does P015B mean in the supplied record?
Its verified title and meaning are “The technician should follow SI diag.” No further code definition is established by the supplied evidence.
Can P015B cause reduced power?
The cited GM communications state that a customer may intermittently report reduced engine power when this group of codes, including P015B, is present. They do not establish that P015B alone always causes reduced power.
What repair fixes P015B?
Not yet established by verified evidence. GM directs technicians to follow the applicable SI diagnostic procedure; a possible charge-air-cooler/induction-system leak is identified for the described concern.