Some 2011 LEAFÂ® vehicles may not go into “READY to drive” mode under certain conditions and, as a result, may not start. Nissan has issued a technical service bulletin addressing this issue, NTB11038. The fix is to have the Vehicle Control Module (VCM) reprogrammed by a Nissan dealer. A side effect of the reprogramming is an improvement in the accuracy of the Driving Range Display.
LEAF shows the master warning light, the yellow triangle warning, the “EV!” system light (yellow car symbol with an exlamation mark), the battery check light, and the PS light. The car seems to function normally (albeit with the warning lights on). However, if you turn off the car at that point, upon power on, you will only be able to select ‘P’ or ‘N’, that is, the car will no longer move.
Pic of dashboard showing warning lights Interwiki: mnl++
Another pic of dashboard showing warning lights Interwiki: mnl++
Another pic of warning lights Interwiki: mnl++
Other ways to deliberately reproduce the problem:
What LEAFs Are Affected
The VINs of reported incidents (where a VIN is reported) appears to be among March deliveries. (The VIN/actual delivery date is from the Google spreadsheet where Leaf buyers/owners record information about their Leaf reservation/order/delivery.)
What To Do
If this happens in your LEAF, do not turn off the car until you have gotten off the road and come to a reasonable parking spot.
After getting off the road and to a reasonable parking place, your best bet is to call Nissan road-side service to have the car towed/transported to a Nissan dealer.
After getting the car to a dealer, tell them about this problem. There’s a software update that apparently fixes, or at least, mitigates, this problem.
After getting the software update, check your charging timers to make sure they were not cleared during the process.
Quick Temporary Fix
If you are in a huge hurry and absolutely cannot wait for a tow, a quick “work-around” is to disconnect the 12V battery’s negative terminal and wait about 10 minutes then re-connect it. (You can use a 10mm wrench or socket to loosen the bolt on the negative terminal’s clamp.) This should allow you to start and operate the car normally again. The 12V power interruption may have “cleared” the error code that prohibits re-start. Also, it’s a good idea to honk the horn and/or turn on the headlights after the terminal is disconnected to bleed off any residual charge in various capacitors. Some people make a “quick disconnect” by adding a wing nut (13mm wrench or socket):
Reports of LEAFs Having/Not Having This Problem
LEAFs having this problem
There have been 22 reports of this “won’t run” problem, from 18 LEAFs:
- In order of VIN:
- welovecats, VIN #430, reported Mon Apr 11, 2011 11:01 pm
- jhm614, VIN #493, reported Thu May 05, 2011 9:39 am
- LindaK, reported Thu Mar 31, 2011 7:26 pm, VIN #531:
- leafwing, reported Sun Mar 27, 2011 7:02 pm: VIN #573
- wq2345, reported Sat Apr 02, 2011 2:43 pm: VIN #00598, delivered Tue Mar 29th
- Azrich, reported Tue Mar 29, 2011 5:45 pm: VIN #604, version 3NA0B
- miku, reported Wed Apr 06, 2011 1:29 am: VIN #716, Mar 30 delivery, had A/C on, “then parked for 3 hours of trickle charge (1-4pm). Decided to take my daughters out for a quick spin too — but 2 miles away, I decided to pull over for a moment, turning off the car. It wouldn’t restart. Didn’t use remote control — just had air con active during the drive.”
Software version reported that have no problem
- Jimmydreams, VIN #175
- TRONZ, VIN #202
- Randy3, VIN #204
- LEAFer, VIN #215, delivery Jan 19, 2011
- ENIAC, VIN #224
- Gonewild, VIN#229
- Uccello, VIN #240, Jan 5, 2011 delivery
- cardw, VIN #254
- evnow, VIN #303, Feb 2011 delivery
- bowthom, VIN #307
- ERG4ALL, VIN #404
- Spies, no issue
- myleaf, VIN #471
- Elofan, VIN #608, Mar 19 delivery
- AndyN, VIN #653, Mar 28, 2010 delivery
- EricH, VIN #664
- bytrain, VIN #668, Mar 26, 2010 delivery
- sdbonez, VIN #728
- jfsquires, VIN #847
- garygid, VIN #855
- rawhog, VIN #868
- Boomer, VIN #889
- ttweed, VIN #1317
- MrFish, VIN #899
- mogur: Mar 2011 delivery
The first report of a dealer visit for this problem mentioned that a salesman said that “the factory overcharged the A/C“. (There was a question as to whether the salesman may have been confused between “A/C” (as in “air conditioning”) and “AC” (as in “alternating current”).)
Another report said “LEAF Tech line told
One car’s A/C system was overcharged. It was recharged. After that, the problem can no longer be reproduced. it is questionable as to whether re-charging is really the fix.
The problem is thought to be related to pre-cooling the car, but there are several counterexamples to that theory:
There has been no report of this problem when pre-heating the car.
Another theory is that a sensor, possibly the Insulation Resistance (IR) sensor, senses a current leak and assumes that there is a short somewhere and thus intervenes to prevent further operation of the car.
The current leak may have been caused by the A/C compressor drawing more current than it should. (The A/C runs off of the high-voltage battery?)
- Current leak detection is set at 380K ohms, “which is quite sensitive”.
- “They typically use a weak AC signal connected from the body alternately to HV+/HV- through a known resistance and read it’s voltage. If the voltage is lower than a certain value the leak detection is triggered. The signal is read with an ADC input on a microcontroller, so the trip threshold is adjustable. This is how it’s done in the Prius as well.”
Diagnostic Trouble Codes (DTCs)
P31E7 RESTART INHIBITION
DTC â€œP3127â€œ is detected with DTC â€œP0AA6â€œ. If DTC â€œP3127â€œ detected, Perform trouble diagnosis for â€œP0AA6â€œ.
Refer to EVC-136, “Description”.
P0AA6 HIGH VOLTAGE SYSTEM ISOLATION
Li-ion battery is equipped with the IR (Insulation resistance) sensing system.
VCM Vehicle Control Module receives the IR sensor signal sent from Li-ion battery controller
and monitors the insulation resistance of the high voltage circuit.
DTC Logic INFOID:0000000006977191
HYBRID BATT VOLT SYS ISOLATION
(High voltage circuit insulation is low)
VCM detects a insulation resistance calculated
based on IR sensor signal sent from Li-ion battery is 380 kW or less.
â€¢ High voltage harness or connectors
â€¢ Electric compressor
â€¢ PTC elements heater
â€¢ Traction motor
â€¢ On-board charger
â€¢ Li-ion battery
â€¢ DC/DC J/B
Other DTCs involved: http://www.mynissanleaf.com/viewtopic.php?p=75863#p75863
Chronology of Diagnoses and Actions
- Apr 22, 2011
- LEAFs brought in for software update show no change to “firmware version number” after reprogramming/update: was on B, is now still B (palmermd). One LEAF reported no change in version (B), but service receipt says “performed vcm reprogram. 237d0-3na0b programed to 237d0-3na0c”.
- Other “version B is still version B after update”:
- Version A is still version A.
- Apr 19, 2011
- Nissan issues a technical service bulletin on the issue, NTB11038, and sends email to some owners:
REASON FOR CAMPAIGN
On some 2011 Nissan LEAF vehicles, a diagnostic programming error may under certain conditions detect a “problem” with the air conditioning system that does not exist, preventing the vehicle from going into “Ready” mode the next time you attempt to start the car. This issue does not occur when the vehicle is being driven. However, the vehicle may not restart after being turned off.
WHAT NISSAN WILL DO
To assure your continued satisfaction and confidence in your car, your EV Certified Nissan Dealer will reprogram the Vehicle ! Control Module free of charge for parts and labor at a time and location that best meets your needs. Typically performed at your Nissan EV Dealer, the reprogramming can also be completed by an EV Certified technician at your home or place of business provided there is a suitable and safe work area. Please discuss with your Nissan EV Dealer regarding timing and location.
This reprogramming will address the failure to restart issue, as well as improve the accuracy of the driving range display.
WHAT YOU SHOULD DO
Contact your EV Certified Nissan Dealer at your earliest convenience in order to arrange your appointment.
This service is free of charge and the work should take about one hour to complete. To ensure the least inconvenience to you, it is important that you have an appointment before bringing your vehicle to the dealer for service. Please bring this notice with you to your service appointment. Detailed instructions have been sent to your EV Certified Nissan Dealer.
If the dealer fails, or is unable to complete the service free of charge, you may contact the Nissan LEAF Call Center, Nissan North America, Inc., P.O. Box 685003, Franklin, TN 37068-5003. The toll free number is 1-877-N0-GAS-EV-(1-877-664-2738).
Thank you for providing us an opportunity to ensure on-going satisfaction with your Nissan LEAF. We are sorry for any inconvenience this may have caused you.
- Apr 17, 2011
- A LEAF delivered (Saturday April 16, 2011) runs 3NA0B, as does a LEAF picked up on Apr 17, 2011.
- Apr 15, 2011
- Nissan’s EVP Andy Palmer made accouncement:
Nissan isannouncing a service campaign for the LEAFs…”
- “Nissan has produced almost 8000 LEAFs.”
- “…incidence is in a very small portion of the vehicles…”
- “The issue is nothing to do with safety.”
- “On some occasions, when you key off, the car won’t restart.”
- “We’ve decided to reprogram the software.”
- “We understood the root cause…”
- Apr 07, 2011
- According to a dealership’s forum post, the software update takes an hour.
- The first reported software change was from version 3NA0B to 3NA0C. However, there have been many reports since of software changes that culminate with the LEAF running 3NA0B.
- Apr 4, 2011
- One dealer says: “26 cars were updated today, and that none of the cars with firmware updates have had the issue recur“.
- Apr 2, 2011
- “Nissan sent out an engineer who determined that the car had a ‘high voltage leak’; something a few others have reported here. This caused the EV emergency shutoff to engage. A software system update was performed and voltage parameters reset.”
- “An issue has arisen with the LEAF where the a/c system may not shut off and cause the car to go into failsafe mode and be inoperable. There is updated software to correct this issue, so we need you to bring in your vehicle for this. To prevent this from possibly happening please do not turn on the a/c or defrost system until the reprogramming is done.”
- “2 engineers from Japan were making the rounds reprogramming PCM on newly delivered Leafs.”
- “Nissan called the dealership today and confirmed that there was a problem and that a software fix is available.”
- “Found two DTCs in system: P31E7 and P0AA6. Contacted Nissan EV Engineering Dept. Found concern only a software issue. Downloaded new software from Nissan and cleared DTCs. Tested vehicle and confirmed condition no logner present.”
- “It would appear that the VCM is falsely sensing that the A/C compressor has an electrical leak to ground.“
- “Engineering is working on this, and will release updated software to solve this problem.”
- Apr 1, 2011
- “The AC is not coordinating with the engine, causing an EV system failure that shuts down the whole thing as if I had an accident“.