Volvo U029E
Lost Communication With NOx Sensor “A” U029E00 - Lost Communication With NOx Sensor “B” U02A300 - Lost Communication With PM Sensor Tags u029d-00 u029e-00 u02a3-00 u029d00 u029e00
Quick answer
U029E00 is identified in verified Volvo/Mack manufacturer communication CBR-2201 as “Lost Communication With NOx Sensor ‘B’.” The communication says intermittent U029E00, U029D00, and U02A300 may occur at key-on and can result in SCR inducement and derate; it identifies an EMS software fix. Vehicle-specific applicability is not established by the supplied 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 U029E mean?
U029E00 is identified in verified Volvo/Mack manufacturer communication CBR-2201 as “Lost Communication With NOx Sensor ‘B’.” The communication says intermittent U029E00, U029D00, and U02A300 may occur at key-on and can result in SCR inducement and derate; it identifies an EMS software fix. Vehicle-specific applicability is not established by the supplied evidence.
2. Technical explanation
The supplied official manufacturer communication (CBR-2201, available from August 2022) identifies U029E00 as lost communication with NOx Sensor “B.” It also lists U029D00, lost communication with NOx Sensor “A,” and U02A300, lost communication with the PM sensor. For the vehicles covered by that communication, the stated condition is intermittent occurrence at key-on, with potential SCR inducement and derate. The stated correction is an EMS software fix intended to eliminate the possibility of those intermittent DTCs at key-on. The supplied evidence does not establish a component failure, wiring fault, sensor failure, or any other root cause for an individual vehicle.
3. What system is affected?
Verified evidence identifies communication involving NOx Sensor “B.” The manufacturer communication also refers to EMS software and SCR inducement/derate. A broader system designation is not yet established by verified evidence.
4. How serious is this code?
Unknown. The supplied manufacturer communication states that the listed intermittent DTCs can result in SCR inducement and derate, but it does not provide a severity classification.
5. Symptoms you may notice
- Intermittent U029E00 at key-on is described in the manufacturer communication.
- SCR inducement and derate may result for vehicles covered by the manufacturer communication.
6. Possible causes
- For vehicles covered by CBR-2201, the manufacturer communication identifies an EMS software condition and specifies an EMS software fix to eliminate the possibility of intermittent U029E00, U029D00, and U02A300 at key-on.
- Any other cause is not yet established by verified evidence.
7. Can I still drive the vehicle?
Not yet established by verified evidence. The manufacturer communication states that the listed DTCs can result in derate, but does not state whether driving is safe.
8. Can I charge the vehicle?
Not yet established by verified evidence.
9. What you can safely do
- Record the exact DTC suffix shown by the diagnostic tool; the verified communication specifically identifies U029E00.
- Arrange diagnosis by an authorized or appropriately qualified service provider.
- Ask the service provider to check whether CBR-2201 and its EMS software fix apply to the specific vehicle.
10. Step-by-step troubleshooting
- Confirm whether U029E00 is present and whether it occurs at key-on.
- Check for accompanying U029D00 and U02A300, which are listed together in CBR-2201.
- Determine, through the applicable manufacturer service process, whether the EMS software fix in CBR-2201 applies to the vehicle.
- Further troubleshooting procedures are not yet established by verified evidence.
11. When to contact service
Contact an authorized Volvo/Mack service provider or another appropriately qualified service provider to confirm applicability of CBR-2201 and evaluate the recorded code(s).
12. What the service center may check
- Confirm the stored DTCs, including whether U029E00 occurs at key-on.
- Review whether U029D00 and/or U02A300 are also present.
- Confirm whether the vehicle is within the coverage of CBR-2201.
- Check EMS software status and applicability of the manufacturer-described software fix.
13. Possible repair or resolution
- For vehicles covered by CBR-2201, the documented resolution is an EMS software fix intended to eliminate the possibility of intermittent U029E00, U029D00, and U02A300 at key-on.
- Any additional repair is not yet established by verified evidence.
14. Affected vehicles
- Volvo S60 · 2016–2022 · US
- Volvo S60 · 2021–2022 · US
- Volvo S90 · 2016–2022 · US
- Volvo S90 · 2021–2022 · US
- Volvo V60 · 2016–2022 · US
- Volvo V60 · 2021–2022 · US
- Volvo XC40 · 2016–2022 · US
- Volvo XC40 · 2021–2022 · US
- Volvo XC60 · 2016–2022 · US
- Volvo XC60 · 2021–2022 · US
- Volvo XC90 · 2016–2022 · US
- Volvo XC90 · 2021–2022 · US
15. Related TSBs / service bulletins
- CBR-2201 / NHTSA manufacturer communication MC-10219421-0001, published August 29, 2022: EMS software fix for the possibility of intermittent U029D00, U029E00, and U02A300 at key-on, which may result in SCR inducement and derate.
- CBR-2201 / NHTSA manufacturer communication MC-10219426-0001, published August 29, 2022: same supplied evidence summary and EMS software-fix information.
16. Recall information
- No recall information is established by the supplied verified evidence.
17. Official manufacturer information
Official NHTSA-hosted manufacturer communication: CBR-2201, available from August 2022. https://static.nhtsa.gov/odi/tsbs/2022/MC-10219421-0001.pdf
19. Frequently asked questions
What does U029E00 mean?
The supplied manufacturer communication identifies U029E00 as “Lost Communication With NOx Sensor ‘B’.”
Can U029E00 cause derate?
CBR-2201 states that intermittent U029E00, U029D00, and U02A300 at key-on can result in SCR inducement and derate for vehicles covered by that communication.
Is there an official fix?
CBR-2201 describes an EMS software fix intended to eliminate the possibility of the listed intermittent DTCs at key-on. Applicability to a specific vehicle must be confirmed by service.
Does this evidence prove that the NOx sensor needs replacement?
No. The supplied evidence does not establish sensor replacement as the required repair.