P31E7: Restart inhibition fault on Nissan electric vehicles
P31E7 restart inhibition (Nissan Leaf)
Severity: Inspect soon
The code comes with a Leaf that will not restart, and owners report being stranded. Nissan links it to a battery module, so it is a high-voltage fault for a shop.
P31E7 in short
On the Nissan Leaf, P31E7 means restart inhibition, usually stored with P0AA6, the high-voltage battery isolation code. Nissan's bulletin covers a Leaf that will not start and points to a battery module with a bent retention plate. This is high-voltage work for a Nissan dealer.
The Leaf can inhibit a restart after a fault in the high-voltage system. Nissan's bulletin NTB23-024 says to run diagnosis when the car will not start and P31E7 (restart inhibition) and P0AA6 (HV battery voltage system isolation) are stored in the EV/HEV control module.
The bulletin says to check whether a battery module caused the codes, inspect that module for a bent retention plate and replace it if so. It covers the 2019-2022 Leaf in the cache extract and was amended as NTB23-024A through 2025.
Owners report being stranded, with one 2022 Leaf (the owner says its module was replaced citing the bulletin) seeing the fault return, and replacement packs on a 2017 and 2018 Leaf diagnosed with an internal short.
Pick your make
P31E7 is a manufacturer-specific code: its meaning depends on who built the car.
Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.
Most likely causes
Cause 1: Battery module with a bent retention plate
Supported by vehicle data- Why it ranks here
- Nissan's bulletin says to inspect the module for a bent retention plate and replace it. A 2022 Leaf owner says this was done under warranty.
- What would change this
- Rises if Nissan's diagnosis shows a module triggered the code. Falls if no module triggered it, as the bulletin then does not apply.
Cause 2: Internal short or isolation fault in the high-voltage pack
Possible — needs testing- Why it ranks here
- Two owners say dealers found an internal short or isolation fault in a replacement pack with P0AA6 and P31E7; these are owner accounts.
- What would change this
- Rises if a dealer isolation test fails. Falls if the isolation test passes.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Have a Nissan dealer run the electric-vehicle diagnosis for P31E7 and P0AA6 and ask whether NTB23-024 applies to your VIN.
Warning:Leaf high-voltage parts can cause serious shock or fire. Do not open the battery pack or touch the orange cables.
IfA battery module triggered the codes
It meansNissan's bulletin applies; the module is inspected and replaced if needed.
IfNo module triggered the codes
It meansThe bulletin does not apply; the dealer follows further diagnosis.
Points to: Internal short or isolation fault in the high-voltage pack
Symptoms
- Leaf will not start or restart, sometimes with an EV system warning
How to fix
This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.
On your vehicle
NissanYour car
2019–2025 · Leaf
Supported by vehicle dataNissan bulletins NTB23-024 and 024A cover the Leaf. Four 2017-2022 Leaf owners report P31E7 with no-restart, and some report a replacement pack failing. Bulletin status is not verified.
NTB23-024Status unverified
Vehicle will not start, P31E7 and P0AA6
2019–2022leaf · NHTSA 10234086
Run diagnosis, inspect the battery module for a bent retention plate and replace it if applicable.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
NTB23-024AStatus unverified
Vehicle will not start, P31E7 and P0AA6 (amended)
2019–2025leaf · NHTSA 11004974
Amended version of NTB23-024; the NHTSA summary only says it was amended.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Related codes
P31E7 questions
Can I reset P31E7 myself?
Clearing it will not fix a high-voltage fault. Have a Nissan dealer diagnose it.
Sources and review
- Nissan bulletin NTB23-024, vehicle will not start with P31E7 and P0AA6 (Leaf; NHTSA 10234086)
- NHTSA complaint ODI 11665431
- NHTSA complaint ODI 11750729
- NHTSA complaint ODI 11746566
- NHTSA complaint ODI 11513715
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error