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Chevrolet U1862

up devices causing no power in 4WD low range. • Erratic electric power steering boost potentially associated with codes U21

DriveUnknown. The supplied verified evidence does not establish whether it is safe to drive with U1862.
ChargeUnknown. The supplied verified evidence does not establish whether charging is affected or safe with U1862.
ServiceContact a Chevrolet/GM service provider for vehicle-specific diagnosis, particularly if the SES/MIL/CEL is illuminated, steering assist is erratic, or 4WD Low Range has no power.
Confidence95%

Quick answer

For Chevrolet vehicles listed in the supplied applicability data, U1862 is documented in official GM/NHTSA communications among numerous communication DTCs. The verified bulletin evidence associates it with an SES/MIL/CEL and, in the bulletin’s broader symptom list, possible no power in 4WD Low Range for diesel power-up devices and erratic electric power-steering boost potentially associated with U21 codes. A vehicle-specific diagnosis is required; driving, charging, severity, and repair requirements are not yet established by verified evidence.

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 U1862 mean?

For Chevrolet vehicles listed in the supplied applicability data, U1862 is documented in official GM/NHTSA communications among numerous communication DTCs. The verified bulletin evidence associates it with an SES/MIL/CEL and, in the bulletin’s broader symptom list, possible no power in 4WD Low Range for diesel power-up devices and erratic electric power-steering boost potentially associated with U21 codes. A vehicle-specific diagnosis is required; driving, charging, severity, and repair requirements are not yet established by verified evidence.

2. Technical explanation

The supplied official NHTSA-hosted manufacturer communications, bulletin 13-08-116-001J (April 2024) and revision 13-08-116-001K (March 2025), list U1862 as one of numerous communication DTCs that may be present with an SES, MIL, or CEL. The evidence does not provide a standalone component-level definition, diagnostic procedure, or confirmed repair for U1862. The canonical database wording also references no power in 4WD Low Range and erratic electric power-steering boost, but the bulletin evidence presents these within a broader symptom list rather than proving that either condition occurs on every vehicle with U1862.

3. What system is affected?

A communication-DTC context is established by the official bulletin evidence. A specific affected module or subsystem is not yet established by verified evidence.

4. How serious is this code?

Unknown. The supplied verified evidence does not assign a severity level.

5. Symptoms you may notice

  • SES, MIL, or CEL may be set.
  • U1862 may appear among numerous communication DTCs.
  • The bulletin’s broader symptom list includes no power in 4WD Low Range for diesel power-up devices.
  • The bulletin’s broader symptom list includes erratic electric power-steering boost potentially associated with U21 codes.

6. Possible causes

  • Not yet established by verified evidence.

7. Can I still drive the vehicle?

Unknown. The supplied verified evidence does not establish whether it is safe to drive with U1862.

8. Can I charge the vehicle?

Unknown. The supplied verified evidence does not establish whether charging is affected or safe with U1862.

9. What you can safely do

  • Arrange vehicle-specific diagnosis by a qualified Chevrolet/GM service provider.
  • Record any warning lamps, communication codes, steering behavior, and 4WD Low Range behavior to provide to the service provider.
  • Do not attempt high-voltage system repair based on this code information.

10. Step-by-step troubleshooting

  1. Have a qualified technician retrieve and evaluate all stored DTCs, because the official bulletins describe U1862 among numerous communication codes.
  2. Use the applicable official manufacturer bulletin and vehicle-specific service information during diagnosis. Further troubleshooting steps are not yet established by verified evidence.

11. When to contact service

Contact a Chevrolet/GM service provider for vehicle-specific diagnosis, particularly if the SES/MIL/CEL is illuminated, steering assist is erratic, or 4WD Low Range has no power.

12. What the service center may check

  • Retrieve all diagnostic trouble codes and evaluate U1862 in the context of other communication DTCs.
  • Review official GM bulletin 13-08-116-001K, dated March 2025, and prior revision 13-08-116-001J, dated April 2024, as applicable. Specific inspection and test steps are not included in the supplied evidence.

13. Possible repair or resolution

  • Not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • GM bulletin 13-08-116-001K, published March 31, 2025 and hosted by NHTSA as MC-11017244-0001, lists U1862 among numerous communication DTCs with an SES/MIL/CEL. Source: https://static.nhtsa.gov/odi/tsbs/2025/MC-11017244-0001.pdf
  • GM bulletin 13-08-116-001J, published April 30, 2024 and hosted by NHTSA as MC-11000162-0001, also lists U1862 among numerous communication DTCs. Source: https://static.nhtsa.gov/odi/tsbs/2024/MC-11000162-0001.pdf

16. Recall information

  • No recall information was supplied in the verified evidence.

17. Official manufacturer information

Verified sources are NHTSA-hosted GM manufacturer communications: bulletin 13-08-116-001K (March 2025) and bulletin 13-08-116-001J (April 2024). Supplied applicability lists Chevrolet Blazer, Bolt EUV, Bolt EV, Equinox, Spark, and Volt in the US across overlapping 2011–2026 model-year ranges. Exact applicability for an individual VIN is not established by the supplied evidence.

19. Frequently asked questions

What does Chevrolet U1862 mean?

Official bulletin evidence lists U1862 among numerous communication DTCs that may accompany an SES, MIL, or CEL. A standalone technical definition is not yet established by the supplied verified evidence.

Can U1862 affect steering or 4WD Low Range?

The official bulletin’s broader symptom list includes erratic electric power-steering boost potentially associated with U21 codes and no power in 4WD Low Range for diesel power-up devices. The evidence does not establish that these conditions occur on every vehicle with U1862.

Is U1862 confirmed for Chevrolet Bolt EV or Bolt EUV?

The supplied applicability data includes Chevrolet Bolt EV and Bolt EUV in the US across overlapping 2011–2026 year ranges. Exact model-year and VIN applicability should be confirmed by a Chevrolet/GM service provider.

Is it safe to drive or charge with U1862?

Not yet established by verified evidence.

20. Sources & verification

Verified
Chevrolet U1862: up devices causing no power in 4WD low range. •… | EV Diagnostics