Mitsubishi U1111
MEDIC must remain connected during the cell smoothing procedure (approximately 2 hours). Ensure MEDIC is fully charged or connected to a charging cable. 1. Turn the electric motor
Quick answer
For 2012–2013 Mitsubishi i-MiEV vehicles in the US, U1111 is referenced in Mitsubishi TSB 17-54-003 during the cell-voltage-smoothing procedure. The verified instruction is that MEDIC must remain connected for approximately two hours and be fully charged or connected to its charging cable.
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 U1111 mean?
For 2012–2013 Mitsubishi i-MiEV vehicles in the US, U1111 is referenced in Mitsubishi TSB 17-54-003 during the cell-voltage-smoothing procedure. The verified instruction is that MEDIC must remain connected for approximately two hours and be fully charged or connected to its charging cable.
2. Technical explanation
Verified evidence identifies U1111 as an exception when checking active DTCs before cell voltage smoothing: active DTCs must be troubleshot before the procedure, except U1111 and U1116. During this procedure, MEDIC must remain connected for approximately two hours. The Main Drive battery must not be charged during the procedure; if it is charging, the charging cable must be disconnected before proceeding.
3. What system is affected?
Cell-voltage-smoothing procedure / Main Drive battery service procedure. A specific vehicle system assignment is not yet established by verified evidence.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
Not yet established by verified evidence.
6. Possible causes
- The verified evidence does not establish a vehicle fault cause for U1111. It documents MEDIC connection requirements during the cell-voltage-smoothing procedure.
7. Can I still drive the vehicle?
Not yet established by verified evidence.
8. Can I charge the vehicle?
Do not charge the Main Drive battery while the cell-voltage-smoothing procedure is being performed. Charging status outside that procedure is not yet established by verified evidence.
9. What you can safely do
- If cell voltage smoothing is being performed, keep MEDIC connected for the approximately two-hour procedure.
- Ensure MEDIC is fully charged or connected to its charging cable during the procedure.
- Do not charge the Main Drive battery during the cell-voltage-smoothing procedure.
- Have active DTCs troubleshot before cell voltage smoothing, except U1111 and U1116 as specified by the bulletin.
10. Step-by-step troubleshooting
- Use Mitsubishi’s applicable service procedure for cell voltage smoothing.
- Before beginning cell voltage smoothing, check for active DTCs. The bulletin states that active DTCs other than U1111 and U1116 must be troubleshot first.
- Maintain the MEDIC connection throughout the approximately two-hour smoothing procedure.
- Further diagnostic steps for U1111 are not yet established by verified evidence.
11. When to contact service
Professional service is appropriate if cell voltage smoothing is required or if DTCs other than U1111 or U1116 are active. The verified bulletin describes a MEDIC-based service procedure.
12. What the service center may check
- Check whether the vehicle is undergoing the cell-voltage-smoothing procedure.
- Confirm MEDIC remains connected and has adequate power, either from its own charge or its charging cable.
- Confirm the Main Drive battery is not being charged during smoothing.
- Check for active DTCs that must be addressed before smoothing, excluding U1111 and U1116 per TSB 17-54-003.
13. Possible repair or resolution
- Follow Mitsubishi TSB 17-54-003 cell-voltage-smoothing requirements when applicable.
- No component replacement or specific repair for U1111 is established by the supplied verified evidence.
14. Affected vehicles
- Mitsubishi i-MiEV · 2012–2013 · US
15. Related TSBs / service bulletins
- Mitsubishi TSB 17-54-003, published through NHTSA Manufacturer Communication PDFs MC-10116253 and MC-10115257 on July 26, 2017. It covers cell voltage smoothing and states that U1111 and U1116 are exceptions to the instruction to troubleshoot active DTCs before smoothing.
16. Recall information
No recall relationship is established by verified evidence.
17. Official manufacturer information
Official NHTSA-hosted Mitsubishi communication: https://static.nhtsa.gov/odi/tsbs/2017/MC-10116253-9999.pdf
19. Frequently asked questions
What does U1111 mean for a 2012–2013 Mitsubishi i-MiEV?
The supplied verified evidence associates U1111 with the MEDIC connection requirement during Mitsubishi’s cell-voltage-smoothing procedure: MEDIC must stay connected for approximately two hours and be powered or connected to its charging cable.
Can the Main Drive battery be charged during cell voltage smoothing?
No. TSB 17-54-003 states not to charge the Main Drive battery during the procedure and instructs technicians to disconnect the charging cable if charging is in progress.
Must U1111 be repaired before cell voltage smoothing?
The bulletin states that active DTCs must be troubleshot before smoothing, other than U1111 and U1116.