Nissan Service EV System: Power Reduced
Service EV System: Power Reduced
Quick answer
For applicable 2019–2022 Nissan LEAF vehicles in the US, this message is documented in an official NHTSA manufacturer communication as appearing when updated software detects a state-of-charge (SOC) fluctuation and records a specific EV-battery DTC. The communication states the vehicle may be prevented from recharging or restarting.
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1. What does Service EV System: Power Reduced mean?
For applicable 2019–2022 Nissan LEAF vehicles in the US, this message is documented in an official NHTSA manufacturer communication as appearing when updated software detects a state-of-charge (SOC) fluctuation and records a specific EV-battery DTC. The communication states the vehicle may be prevented from recharging or restarting.
2. Technical explanation
Verified evidence links the warning message “Service EV System: Power Reduced” to detection of an SOC fluctuation by updated software. When detected, the system records a specific EV-battery diagnostic trouble code (DTC) and displays this warning on the vehicle information screen. The supplied evidence does not identify the exact DTC number or provide a complete diagnostic procedure.
3. What system is affected?
Lithium-ion battery / EV battery system.
4. How serious is this code?
Unknown. However, the official communication states that the software may prevent recharging or restarting to ensure safety.
5. Symptoms you may notice
- “Service EV System: Power Reduced” displayed on the vehicle information screen.
- A specific EV-battery DTC recorded when updated software detects an SOC fluctuation.
- Vehicle may be prevented from recharging or restarting.
6. Possible causes
- An SOC fluctuation detected by updated software.
- Further underlying cause is not yet established by verified evidence.
7. Can I still drive the vehicle?
Unknown. Verified evidence states the vehicle may be prevented from restarting.
8. Can I charge the vehicle?
The official communication states the software will prevent the vehicle from recharging when the relevant SOC fluctuation is detected.
9. What you can safely do
- Do not rely on the vehicle being able to restart or accept a charge after this message appears.
- Arrange professional diagnosis by a Nissan dealer or qualified EV service provider.
- Do not attempt high-voltage battery repair or disassembly.
10. Step-by-step troubleshooting
- Have the vehicle scanned for EV-battery DTCs using appropriate diagnostic equipment.
- Confirm whether the condition involves the software-detected SOC fluctuation described in the official manufacturer communication.
- Further owner-performed troubleshooting is not yet established by verified evidence.
11. When to contact service
Contact a Nissan dealer or qualified EV service provider, particularly because the documented condition can prevent charging or restarting.
12. What the service center may check
- Read stored EV-battery DTCs.
- Assess whether updated software detected an SOC fluctuation.
- Check applicable Nissan manufacturer communications for the vehicle's VIN and configuration.
13. Possible repair or resolution
- The supplied evidence confirms a software-related detection condition but does not establish a specific repair or final resolution.
- Repair details are not yet established by verified evidence.
14. Affected vehicles
- Nissan Leaf · 2019–2022 · US
15. Related TSBs / service bulletins
- NHTSA Manufacturer Communication 11034255, titled “Lithium - ion Battery,” published June 3, 2026. It states that if updated software detects an SOC fluctuation, a specific EV-battery DTC is recorded, “Service EV System: Power Reduced” is displayed, and the vehicle is prevented from recharging or restarting.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Official source: NHTSA Manufacturer Communication 11034255, “Lithium - ion Battery” (Nissan), published June 3, 2026: https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11034255
19. Frequently asked questions
What does “Service EV System: Power Reduced” mean on an applicable Nissan LEAF?
The supplied official communication states that updated software displays this message when it detects an SOC fluctuation and records a specific EV-battery DTC.
Can the vehicle charge with this message displayed?
The official communication states that the software will prevent the vehicle from recharging when the relevant condition is detected.
Can the vehicle restart after this message?
The official communication states that the software will prevent the vehicle from restarting when the relevant condition is detected.
Which vehicles are covered by the supplied applicability evidence?
Nissan LEAF model years 2019 through 2022 in the United States. VIN-specific applicability is not yet established by verified evidence.