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Chevrolet P0402

The technician should follow SI diagnostics. If no cause for the concern is found or during diagnosis a l

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceService need is listed as unknown in the supplied diagnostic record. Seek qualified Chevrolet service if the MIL is illuminated or reduced engine power is occurring.
Confidence95%

Quick answer

For Chevrolet vehicles covered by the supplied applicability data, P0402 is listed in GM bulletin PIP5684/PIP5684A/B/C among possible current or history codes associated with an illuminated MIL and, intermittently, reduced engine power. The bulletin says a charge-air-cooler/induction-system leak may be the cause and directs technicians to follow SI diagnostics. The supplied evidence does not establish a code-specific definition for P0402.

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 P0402 mean?

For Chevrolet vehicles covered by the supplied applicability data, P0402 is listed in GM bulletin PIP5684/PIP5684A/B/C among possible current or history codes associated with an illuminated MIL and, intermittently, reduced engine power. The bulletin says a charge-air-cooler/induction-system leak may be the cause and directs technicians to follow SI diagnostics. The supplied evidence does not establish a code-specific definition for P0402.

2. Technical explanation

Verified NHTSA-posted GM manufacturer communications PIP5684, PIP5684A, PIP5684B, and PIP5684C list P0402 as one of many possible current or history DTCs. In the bulletin context, a vehicle may be presented for an illuminated MIL, and the customer may intermittently report reduced engine power. GM states that the concern may be due to a leak in the charge air cooler/induction systems. The correction is to follow SI diagnostics; the supplied excerpt is truncated after stating that if no cause is found, or during diagnosis, additional direction applies. No further diagnostic or repair detail is established by the supplied evidence.

3. What system is affected?

The bulletin identifies the charge air cooler/induction systems as a possible area of concern. A definitive P0402 system assignment is not yet established by verified evidence.

4. How serious is this code?

Unknown. The supplied diagnostic record does not establish severity.

5. Symptoms you may notice

  • Illuminated MIL may be present.
  • Intermittent reduced engine power may be reported.
  • The bulletin lists P0402 as a possible history or current code; these symptoms are not established as exclusive to P0402.

6. Possible causes

  • A leak in the charge air cooler/induction systems may be the cause in the bulletin scenario.
  • Any other cause is not yet established by verified evidence.

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 applicable Chevrolet service information (SI).
  • Do not assume the charge air cooler/induction-system leak is confirmed solely because P0402 is stored.

10. Step-by-step troubleshooting

  1. A qualified technician should follow Chevrolet SI diagnostics, as directed by GM bulletin PIP5684 series.
  2. The supplied evidence does not establish safe vehicle-owner diagnostic steps or component-testing procedures.

11. When to contact service

Service need is listed as unknown in the supplied diagnostic record. Seek qualified Chevrolet service if the MIL is illuminated or reduced engine power is occurring.

12. What the service center may check

  • Retrieve and evaluate current and history DTCs in accordance with Chevrolet SI diagnostics.
  • Follow SI diagnostics for the concern, as directed in PIP5684/PIP5684A/B/C.
  • Evaluate for a charge air cooler/induction-system leak only as supported by the applicable SI diagnostic process.

13. Possible repair or resolution

  • The verified bulletin direction is to follow SI diagnostics.
  • A specific repair, replacement part, or confirmed resolution is not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • GM PIP5684, NHTSA manufacturer communication MC-10167455, published 2019-10-22: https://static.nhtsa.gov/odi/tsbs/2019/MC-10167455-9999.pdf
  • GM PIP5684A, NHTSA manufacturer communication MC-10176300, published 2020-05-05: https://static.nhtsa.gov/odi/tsbs/2020/MC-10176300-9999.pdf
  • GM PIP5684B, NHTSA manufacturer communication MC-10178370, published 2020-07-13: https://static.nhtsa.gov/odi/tsbs/2020/MC-10178370-9999.pdf
  • GM PIP5684C, NHTSA manufacturer communication MC-10182564, published 2020-10-22: https://static.nhtsa.gov/odi/tsbs/2020/MC-10182564-9999.pdf

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Supplied applicability data identifies US Chevrolet Bolt EV, Spark, and Volt model years 2011–2018. The PIP5684-series bulletin evidence should be confirmed against the specific vehicle and its applicable Chevrolet SI information.

19. Frequently asked questions

What does P0402 mean here?

The supplied diagnostic record contains a truncated canonical meaning and does not establish a complete code definition. The GM bulletins list P0402 among many possible current or history codes in a particular MIL/reduced-power diagnostic scenario.

Can a charge air cooler or induction leak cause P0402?

GM states that such a leak may be the cause of the bulletin concern, where P0402 is one of many listed codes. It is not confirmed as the cause for every vehicle with P0402.

Is reduced power possible?

The bulletin states that a customer may intermittently comment that the engine has reduced power. It does not establish that reduced power will occur with every P0402 event.

Is there a recall for this issue?

Not yet established by verified evidence.

20. Sources & verification

ReferenceVerified
Chevrolet P0402: The technician should follow SI diagnostics. If no… | EV Diagnostics