Toyota U0129
2021 model year Highlander, Highlander Hybrid, RAV4, and RAV4 Hybrid; and 2021 model year RAV4 Prime vehicles equipped with Premium Audio (version 1383) may experience the follow
Quick answer
For certain Toyota vehicles, U0129 is documented by Toyota as an intermittent DTC that may occur with Premium Audio head-unit software version 1383. Toyota’s documented remedy is an Audio Head Unit Software Update (Denso-Ten).
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 U0129 mean?
For certain Toyota vehicles, U0129 is documented by Toyota as an intermittent DTC that may occur with Premium Audio head-unit software version 1383. Toyota’s documented remedy is an Audio Head Unit Software Update (Denso-Ten).
2. Technical explanation
The supplied official Toyota/NHTSA service-bulletin evidence lists U0129 among intermittent DTCs associated with specified Premium Audio software behavior. The evidence does not establish a generic subsystem definition for U0129 in this context, nor does it establish that every occurrence has the same cause.
3. What system is affected?
Premium Audio / multimedia head unit software (Denso-Ten), where the bulletin’s applicability and software-version conditions are met.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
- U0129 may be intermittent.
- The bulletin also documents possible abnormal charging-icon operation on the charging screen.
- Audio information may not display on the meter “Audio” tab.
- There may be a delay when turning off HVAC “AUTO” from the multimedia screen.
- HVAC settings may display differently after the last ACC-OFF.
- HVAC blower-motor operation may not display while in “AUTO.”
- Bluetooth may not reconnect after an Android Auto phone call.
- Bluetooth audio may continue playing after connecting and disconnecting Android Auto.
6. Possible causes
- On covered vehicles equipped with Premium Audio version 1383, Toyota associates the documented condition with audio head-unit software. 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
- Record whether U0129 is intermittent and note any multimedia, meter-display, HVAC-display, Bluetooth, or charging-screen behavior.
- Arrange Toyota dealer or qualified service evaluation to confirm vehicle applicability and installed head-unit software.
- Do not attempt high-voltage system repair based on this DTC or bulletin evidence.
10. Step-by-step troubleshooting
- Confirm the model year, model, region, Premium Audio equipment, and installed audio-head-unit software version.
- Check whether Toyota Audio Head Unit Software Update (Denso-Ten), T-SB-0019-21 or its revision, applies.
- The supplied evidence does not establish further diagnostic steps.
11. When to contact service
Contact a Toyota dealer or qualified Toyota service provider to verify applicability of T-SB-0019-21 Revision 2 / Audio Head Unit Software Update (Denso-Ten).
12. What the service center may check
- Verify whether the vehicle is within the bulletin’s covered vehicle and equipment configuration.
- Verify whether Premium Audio software version 1383 is installed.
- Assess whether the reported intermittent U0129 and documented multimedia-related behaviors are present.
- Determine whether the applicable Audio Head Unit Software Update is needed.
13. Possible repair or resolution
- Toyota’s documented resolution is an Audio Head Unit Software Update (Denso-Ten) when the bulletin applies.
- The supplied evidence does not establish any parts replacement or high-voltage repair requirement.
14. Affected vehicles
- Toyota Prius Prime · 2021–2022 · US
- Toyota Prius Prime · 2021 · US
- Toyota RAV4 Prime · 2021–2022 · US
- Toyota RAV4 Prime · 2021 · US
15. Related TSBs / service bulletins
- Toyota T-SB-0019-21 Rev / Rev2, Audio Head Unit Software Update (Denso-Ten). NHTSA manufacturer communication PDFs: MC-10201369 (published July 9, 2021) and MC-10204562 (published November 12, 2021).
- The supplied summaries identify intermittent U0129 among DTCs addressed in the bulletin.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Official NHTSA-hosted Toyota bulletin: https://static.nhtsa.gov/odi/tsbs/2021/MC-10204562-9999.pdf
19. Frequently asked questions
Is U0129 documented as intermittent?
Yes. The supplied Toyota bulletin evidence lists U0129 among intermittent DTCs.
Does the evidence identify a repair?
Yes. The bulletin is titled Audio Head Unit Software Update (Denso-Ten), and the documented resolution is a head-unit software update when applicable.
Does U0129 prove there is a high-voltage battery or charging-system fault?
No. The supplied evidence does not establish that conclusion.
Which supplied applicability records include Prius Prime?
The supplied applicability data includes US-specification 2021 Prius Prime and 2021–2022 Prius Prime records.
Which supplied applicability records include RAV4 Prime?
The supplied applicability data includes US-specification 2021 RAV4 Prime and 2021–2022 RAV4 Prime records. The cited bulletin summary specifically references 2021 RAV4 Prime vehicles equipped with Premium Audio version 1383.