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Mazda B119F

01 (TEL antenna No.1 malfunction) stored. This may be caused by an aftermarket dash cam. The aftermarket device may cause electrical noise disturbing the reception of GPS signals

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact a Mazda dealer or qualified service provider for diagnosis, particularly if the master warning light or “In-Vehicle Network Malfunction” message is displayed or B119F:01 returns.
Confidence95%

Quick answer

Mazda DTC B119F:01 is identified in verified Mazda/NHTSA service communications as “TEL antenna No.1 malfunction.” Mazda documents that aftermarket equipment—such as a dash cam, radar detector, or FasTrak device—may create electrical noise that disturbs GPS-signal reception.

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 B119F mean?

Mazda DTC B119F:01 is identified in verified Mazda/NHTSA service communications as “TEL antenna No.1 malfunction.” Mazda documents that aftermarket equipment—such as a dash cam, radar detector, or FasTrak device—may create electrical noise that disturbs GPS-signal reception.

2. Technical explanation

The supplied verified evidence specifically concerns the B119F:01 subcode, not every possible B119F variant. Mazda service communications describe B119F:01 as a TEL antenna No.1 malfunction and identify electrical interference from certain aftermarket devices as a possible contributor. The evidence does not establish that the vehicle’s antenna itself has failed, nor does it establish a single repair for every occurrence.

3. What system is affected?

TEL antenna No.1 / GPS-signal reception. The supplied evidence does not further establish the exact component architecture or module affected.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • The master warning light may illuminate.
  • An “In-Vehicle Network Malfunction” warning message may appear in the instrument cluster.
  • DTC B119F:01 may be stored.

6. Possible causes

  • An aftermarket dash cam may cause electrical noise that disturbs reception of GPS signals.
  • Mazda communications also identify a radar detector and/or FasTrak device as possible sources of electrical noise associated with B119F:01.
  • Not every B119F:01 event is established by verified evidence to be caused by aftermarket equipment.

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

  • If fitted, identify aftermarket equipment mentioned in Mazda communications, including a dash cam, radar detector, FasTrak device, or aftermarket GPS device.
  • Arrange diagnosis by a Mazda dealer or qualified service provider if the warning light/message is present or the code returns.
  • Do not attempt antenna, CMU, wiring, or high-voltage-system repairs yourself.

10. Step-by-step troubleshooting

  1. A service provider can confirm the exact stored subcode; the verified evidence specifically identifies B119F:01.
  2. Mazda service communications direct technicians to consider/remove aftermarket GPS devices that may interfere with the vehicle GPS antenna.
  3. For a separate B119F:49 diagnostic path, Mazda communications describe obtaining CMU log and backup data where possible before CMU replacement, and replacing the GPS antenna if the diagnostic result indicates it. This does not establish that this procedure applies to B119F:01.

11. When to contact service

Contact a Mazda dealer or qualified service provider for diagnosis, particularly if the master warning light or “In-Vehicle Network Malfunction” message is displayed or B119F:01 returns.

12. What the service center may check

  • Confirm whether B119F:01 is stored.
  • Check for relevant aftermarket accessories and potential interference, as directed by Mazda communications.
  • Use Mazda service information for the vehicle-specific diagnostic process.
  • For B119F:49 only, Mazda communications describe retrieving CMU log/backup data where possible before CMU replacement and evaluating whether GPS-antenna replacement is indicated.

13. Possible repair or resolution

  • If verified interference from an aftermarket device is found, removal of the interfering device is identified in Mazda communications as a relevant action.
  • Not yet established by verified evidence whether removal will resolve every B119F:01 case.
  • GPS-antenna replacement is documented in supplied Mazda communications for a B119F:49 diagnostic outcome, not as a confirmed repair for B119F:01.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Mazda SA-032-23, NHTSA manufacturer communication 10237216, published May 24, 2023: identifies B119F:01 TEL antenna No.1 malfunction and states an aftermarket dash cam may create electrical noise that disturbs GPS reception.
  • Mazda SA-032-23a, NHTSA manufacturer communication 10244679, published October 11, 2023: identifies dash cams, radar detectors, and/or FasTrak devices as possible contributors to B119F:01 through electrical noise affecting GPS reception.
  • Mazda SA-038-24, NHTSA manufacturer communication 11003361, published June 14, 2024: documents master warning and/or “In-Vehicle Network Malfunction” messaging with B119F:01 stored.
  • Mazda SA-057-24 / SA-061-25 / SA-041-26 include the same aftermarket-device example for B119F:01 in the supplied evidence.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified official manufacturer communications are available through NHTSA, including 10237216 (SA-032-23), 10244679 (SA-032-23a), and 11003361 (SA-038-24).

19. Frequently asked questions

What does Mazda code B119F:01 mean?

Verified Mazda/NHTSA communications identify B119F:01 as “TEL antenna No.1 malfunction.”

Can a dash cam cause B119F:01?

Mazda communications state that an aftermarket dash cam may cause electrical noise that disturbs GPS-signal reception and may be associated with B119F:01.

Are radar detectors or FasTrak devices relevant?

Yes. Supplied Mazda communications identify a radar detector and/or FasTrak device as possible sources of electrical noise associated with B119F:01.

Is it safe to drive or charge with B119F:01?

Not yet established by verified evidence.

Does B119F:01 prove the TEL antenna has failed?

No. The supplied evidence identifies the code description and possible aftermarket electrical interference, but does not establish antenna failure in every case.

20. Sources & verification

Verified
Show all 15 verified sources
Mazda B119F: 01 (TEL antenna No.1 malfunction) stored. This may be… | EV Diagnostics