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Tesla DI_w039

Regenerative braking unavailable Use brake pedal as needed

Common search variants: DIw039 · DI-w039 · DI w039 · Search ignores case and common separators.

DriveNot yet established by the supplied diagnostic record. Verified owner-manual evidence instructs the driver to use the brake pedal as needed; it does not provide a general drive/no-drive determination for DI_w039 in the supplied excerpts.
ChargeNot yet established by verified evidence.
ServiceIf DI_w039 persists throughout subsequent drives, Tesla owner-manual communications instruct scheduling service at the earliest convenience.
Confidence95%

Quick answer

Tesla alert DI_w039 means regenerative braking performance is temporarily reduced, so the vehicle provides less automatic deceleration when the accelerator is released. Use the brake pedal as needed.

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 DI_w039 mean?

Tesla alert DI_w039 means regenerative braking performance is temporarily reduced, so the vehicle provides less automatic deceleration when the accelerator is released. Use the brake pedal as needed.

2. Technical explanation

Verified Tesla owner-manual communications filed with NHTSA describe DI_w039 as a temporary reduction in regenerative braking performance. When it is active, lifting off the accelerator produces less automatic deceleration than expected. The alert text is: “Regenerative braking unavailable Use brake pedal as needed.”

3. What system is affected?

Regenerative braking system.

4. How serious is this code?

Severity is not established by the supplied diagnostic record. The verified owner-manual information describes reduced regenerative braking performance and instructs the driver to use the brake pedal as needed.

5. Symptoms you may notice

  • DI_w039 alert: “Regenerative braking unavailable Use brake pedal as needed.”
  • Less automatic deceleration when lifting off the accelerator pedal while driving.
  • Temporarily reduced regenerative braking performance.

6. Possible causes

  • The high-voltage battery is near full charge. Verified Tesla owner-manual information states that regenerative braking is reduced in this condition.
  • Other causes are not yet established by verified evidence.

7. Can I still drive the vehicle?

Not yet established by the supplied diagnostic record. Verified owner-manual evidence instructs the driver to use the brake pedal as needed; it does not provide a general drive/no-drive determination for DI_w039 in the supplied excerpts.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • Use the brake pedal as needed because automatic deceleration is reduced.
  • Allow for the reduced regenerative braking effect when lifting off the accelerator.
  • If the alert persists throughout subsequent drives, schedule service at your earliest convenience.

10. Step-by-step troubleshooting

  1. Check whether the high-voltage battery is near full charge; verified Tesla information identifies this as a condition in which regenerative braking is reduced.
  2. Monitor whether the alert persists through subsequent drives.
  3. No further owner troubleshooting is established by verified evidence.

11. When to contact service

If DI_w039 persists throughout subsequent drives, Tesla owner-manual communications instruct scheduling service at the earliest convenience.

12. What the service center may check

  • Not yet established by verified evidence.

13. Possible repair or resolution

  • Not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • NHTSA manufacturer communication MC-10253660-9999, published March 26, 2024: Tesla owner-manual information describing DI_w039.
  • NHTSA manufacturer communication MC-10253658-9999, published March 26, 2024: Tesla owner-manual information describing DI_w039.
  • NHTSA manufacturer communication MC-10250483-9999, published December 1, 2023: Tesla owner-manual information stating that reduced regenerative braking may occur when the high-voltage battery is near full charge.
  • The supplied sources are manufacturer communications/owner-manual documentation filed with NHTSA; no repair-specific service procedure is established by the supplied evidence.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified NHTSA-filed Tesla owner-manual communications state that DI_w039 indicates temporarily reduced regenerative braking and less automatic deceleration on accelerator lift-off. They identify a near-full high-voltage battery as a condition that can reduce regenerative braking and advise using the brake pedal as needed. Source example: NHTSA MC-10250483-9999, https://static.nhtsa.gov/odi/tsbs/2023/MC-10250483-9999.pdf

19. Frequently asked questions

What does Tesla DI_w039 mean?

It means regenerative braking performance is temporarily reduced, resulting in less automatic deceleration when the accelerator is released.

Why can DI_w039 appear?

Verified Tesla owner-manual information states that it may occur when the high-voltage battery is near full charge, because regenerative braking is reduced in that condition. Other causes are not yet established by verified evidence.

What should the driver do?

Use the brake pedal as needed. If the alert persists throughout subsequent drives, schedule service at the earliest convenience.

Can I charge with DI_w039?

Not yet established by verified evidence.

20. Sources & verification

Verified
Show all 24 verified sources
Tesla DI_w039: Regenerative braking unavailable Use brake pedal as… | EV Diagnostics