Mazda U3004
ACC RELAY CIRCUIT MALFUNCTION○ U0415:00 - MAZDA RADAR CRUISE CONTROL (MRCC)/SMART BRAKE SUPPORT (SBS)○ U0420:00 - MAZDA RADAR CRUISE CONTROL (MRCC)/SMART BRAKE SUPPORT (SBS)○ Multi
Quick answer
For certain U.S. 2022–2024 Mazda CX-90 and MX-30 vehicles, Mazda service communications list DTC U3004:17 as “ACC relay circuit malfunction.” The communications identify an aftermarket device connected to DLC-2 as a possible contributor because it may spread the DLC-2 female terminals open.
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 U3004 mean?
For certain U.S. 2022–2024 Mazda CX-90 and MX-30 vehicles, Mazda service communications list DTC U3004:17 as “ACC relay circuit malfunction.” The communications identify an aftermarket device connected to DLC-2 as a possible contributor because it may spread the DLC-2 female terminals open.
2. Technical explanation
The verified evidence specifically identifies U3004:17, a sub-code of U3004, as an ACC relay circuit malfunction. Mazda service communications also list U0415:00, U0420:00, and multiple U0XXX:00 communication errors in the same diagnostic context. The documented concern is that an aftermarket device connected to DLC-2 may cause the DLC-2 female terminals to spread open.
3. What system is affected?
ACC relay circuit; the supplied evidence does not further establish the affected vehicle subsystem.
4. How serious is this code?
Unknown. The supplied verified evidence does not assign a severity level.
5. Symptoms you may notice
- A stored U3004:17 DTC may be present.
- The supplied evidence also lists U0415:00, U0420:00, and multiple U0XXX:00 communication-error DTCs in the same service-communication context.
- Other customer-visible symptoms are not yet established by verified evidence.
6. Possible causes
- An aftermarket device connected to DLC-2 may cause DLC-2 female terminals to spread open.
- Other causes are 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
- Check whether an aftermarket device is connected to DLC-2.
- Mazda’s service communication says to advise the customer to remove an aftermarket device found connected to DLC-2.
- Do not attempt high-voltage repairs based on this information.
10. Step-by-step troubleshooting
- Confirm the exact stored DTC, including whether it is U3004:17.
- Check for an aftermarket device connected to DLC-2.
- If an aftermarket device is found, Mazda’s communication instructs technicians to photograph it and attach the photo to the repair order, then advise the customer to remove the device.
- Further diagnostic steps are not yet established by verified evidence.
11. When to contact service
Contact a Mazda dealer or qualified service provider if U3004:17 is stored, particularly if no aftermarket device is connected to DLC-2 or if codes remain after the device is removed.
12. What the service center may check
- Verify whether an aftermarket device is connected to DLC-2.
- Inspect the DLC-2 connection in accordance with Mazda service procedures; the verified communication notes that female terminals may be spread open.
- Review for the DTCs listed in the Mazda communication, including U3004:17, U0415:00, U0420:00, and multiple U0XXX:00 communication errors.
13. Possible repair or resolution
- Mazda’s verified service communication directs that a customer be advised to remove an aftermarket device found connected to DLC-2.
- Any additional repair resolution is not yet established by verified evidence.
14. Affected vehicles
- Mazda CX-90 · 2022–2024 · US
- Mazda MX-30 · 2022–2024 · US
15. Related TSBs / service bulletins
- Mazda Service Alert SA-032-23, published May 24, 2023: NHTSA Manufacturer Communication 10237216. https://static.nhtsa.gov/odi/tsbs/2023/MC-10237216-0001.pdf
- Mazda Service Alert SA-032-23a, published October 11, 2023: NHTSA Manufacturer Communication 10244679. https://static.nhtsa.gov/odi/tsbs/2023/MC-10244679-0001.pdf
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
The supplied official NHTSA-hosted Mazda manufacturer communications apply in the provided database to U.S. 2022–2024 Mazda CX-90 and MX-30 vehicles. They list U3004:17 and describe potential DLC-2 terminal spreading associated with an aftermarket device connected to DLC-2.
19. Frequently asked questions
What does U3004:17 mean in the supplied Mazda evidence?
It is listed as “ACC relay circuit malfunction.”
What documented factor can be associated with U3004:17?
Mazda’s service communication states that an aftermarket device connected to DLC-2 may spread open DLC-2 female terminals.
Is U3004:17 confirmed to make the vehicle unsafe to drive or charge?
Not yet established by verified evidence.
Which vehicles are covered by the supplied applicability data?
U.S. 2022–2024 Mazda CX-90 and MX-30 vehicles.
Is this a recall?
Not yet established by verified evidence. The supplied records are manufacturer communications/service alerts, not recall evidence.