2014 no start - error P31E1 - interlock?

[arnis]

Now is my turn to cry

C118C and C1A6E and C1A70 - general error due to ABS not working?

And

P3180 000B HV Battery System EVC-249
P31E1 000B HV System Interlock Error EVC-305
P0A0D 004E HV BATTERY HV Sys Interlock Err EVB-70
Car was resting under hot sun for 8 hours, started and was in READY for 2-3 seconds (Power Steering available).
Then shut down. And will not start. Errors can not be deleted.
Tried to reset by 12V battery disconnection. No help.

It appears that something is wrong just with the interlock. No other meaningful errors :|
Can interlock loop be tapped/tested under the hood/service disconnect plug?

235 000km 145 000 miles and SOH 83% - this EV shall be fixed and serve for another decade

 

[MikeinPA]

I had the P31E1 000B HV System Interlock Error EVC-305 error 4 weeks ago and resolved it fairly easily. In my case, the interlock was physically broken. Here is the fix and I will add the photos shortly if I can figure out how to do so.

On the front of the battery pack are three connectors. The connector on the right goes to the PTC (there are two power wires which are the purpose of the connector). There is also an interlock circuit built into the connector which checks to make sure the connector is seated. The interlock includes a small grey wire, which my case had corroded through. See page EVB-27 of this document https://www.speakev.com/attachments/nissan-leaf-technical-manual-evb-pdf.139268/ for the interlock circuit this DTC is referring to.

A good image of a corroded grey wire https://autosphere.ca/wp-content/uploads/2022/08/batterie-haute-tension_circuit-interlock_WP-2.jpg

The wire is on top of the PTC cable and difficult to see without disconnecting the PTC cable and pulling it down. In my case I had to very closely examine the wire and did find it was completely rotted through--although the insulation was still visibly intact. I have preserved the failed wire to look at under magnification if anyone is interested. I suspect the plastic insulation is defective somehow, and cracks where it was stressed during installation.

So,

>>>disconnect the 12 V

>>>drop the front splash shield (first of three shields on the battery--not the one under the motor)

>>>put on your HV gloves, pull the safety disconnect between the rear seats. Be patient with figuring out the safety disconnect, there is a latch under the latch that needs to be tickled before the handle will swing up freely. It feels stuck somehow, but there is a hidden latch.

>>>Under the car, pull the PTC connector off, and check that grey wire very carefully. See page EVB-183 of this document to work the latch on the PTC connector https://www.speakev.com/attachments/nissan-leaf-technical-manual-evb-pdf.139268/ Use a bright light and wear safety glasses. Road grit is going to fall off that connector and right into your Mark 1s.

I shortened the grey wire to remove the damage, soldered it, and heat-shrinked it. The only tricky part is grasping the stubs of grey wire in order to use the wire strippers. I used a pair of needle nose pliers with tapes on the jaws to gently but firmly grasp the grey wire while stripping it--this way no stress is placed on the part of the grey wire going into the connector. Use marine heat shrink and protect the rest of the cable with numinum foil before applying heat. Tape the shortened grey wire down to the connector shell. Reconnect everything, codes could now be cleared.

If the grey wire fails closer to the connector, then it will likely be necessary to de-pin and install a new interlock wire. Or, perhaps, de-pin the power conductors and use a new connector.

Mods, please update the OP's title to read "P31E1 000B HV System Interlock Error EVC-305--2013, 2014--no start"

 

[Stanton]

A good image of a corroded grey wire https://autosphere.ca/wp-content/uploads/2022/08/batterie-haute-tension_circuit-interlock_WP-2.jpg

Outstanding write-up!
I gotta ask: where did all that corrosion come from? It looks like something that was submerged in water for 50 years! I have that particular plug "siliconed" (not used) from when I upgraded my battery pack (my version of the Leaf doesn't support that connection).

 

[MikeinPA]

Thanks Stanton. Also, thanks to this board and others out there for helping me zero in on this.

The corrosion was complete. Just green powder inside the insulation--and I had to bend the wire to create enough of a gap to see the green powder. I was very happy at that point--confident I had found the problem. As reference, corrosion under the car is normal for 9 NE winters--so no unusual environmental conditions. Also, no physical damage or any thing else out of the ordinary I could see.

Why corroded? I do have the piece I cut off and will get a look at to see if there is micro cracking. Also, the grey wire is part of loop running adjacent to high voltage/high current, so maybe there is some sort of induced current or eddies in the wire, heating it up. My grey wire failed at the point where it was bent 90 degrees to conform with the connector shell.

More generally, I think this interlock was added with the 2013 model when Nissan ran the cable to the PTC directly. Previously, power to the PTC came from some other place (the inverter?) So they added the PTC cable, and then needed an interlock detection. Hence the grey wire which looks like a complete afterthought to me. Like "oops, better add an interlock to this connector".

 

[arnis]

Thanks for all the tips :idea:

Bad news, multimeter said that interlock pins of PTC plug are shorted, as they should be.



What about other reasonable corrosion spots:

LB6 is the service plug in the middle of the pack.
LB4 is the plug for PTC heater, with the tiny wire.
LB2 is the plug in the middle, next to PTC heater plug?
What about other end of that plug. There are other HV connections that should be in the chain, what the heck.
Just 3 plugs?


EDIT: On 28th of March same error occurred during night charging session. Charging stopped at around 40%.
Car started in the morning, but error codes were stored. P0A0D, P3180 AND P31E1, aka the same.
It all hints to corrosion.

BTW, good website to upload your photos and to share them on forums.

 

[MikeinPA]

Arnis, sorry to hear that did not solve it. Although the BMS/LBC may be doing something more complex than simply checking continuity. This reference at openinverter https://openinverter.org/forum/viewtopic.php?t=370 found

Well it's not all magic, I actually traced the interlock signal. It is a 3.3333333Hz 50/50 PWM on the source. It is then routed via the various interlock switches back to the LBC, through a transistor to the MCU. Behind the transistor the signal was swinging between 4.5 and 5V which didn't seem right. So I beefed up the base voltage divider. Now a nice 0-5V swing is generated. Not sure what the deal is.

so even if your multimeter can find continuity, the BMS/LBC might not see what it is looking for. I will check the piece of grey wire I cut out with my Fluke--right now that is in a toolbag that is offsite. Here is a picture of my grey wire after I had bent it enough to expose the green copper corrosion product.



You did check the service plug of course. Little chance that connection would be broken.

The third interlock is built into LB2, the main HV socket and may only connect once the plug is fully in and fastened. The following two images are views of the main HV socket from outside the battery enclosure and from the inside:





yes, good image hosting service, although the links will expire?

 

[arnis]

No they do not expire. Create account to store personal photos. And if necessary, delete them, then link will expire.
I have some 5yo stuff there still available for forums

Many thanks for PWM information. I do have a tiny oscillograph, will measure PWM signal soon.
5V expected and to ground or only somehow floating receiving end pin?



What happens if I try to unfasten the aluminum frame for plugs? Will it allow me to pull it away far enough to see
corrosion/damage on the other side?
I'll to anything to NOT DROP the battery and cut the lid off :|

 

[arnis]

Soo, it gets more interesting.
If I short PDM pin1 and Service plug pin3, diagnostics states that interlock is closed.
If I use the service plug and short PDM pin1 to PTC pin2, interlock is closed.
If I attach PTC plug with clean copper wire and short PDM pins, interlock stays open.
If I attack PDM plug and short PTC pins, interlock stays open.

If I measure correct waveform, it oscillates 5V. If I measure between PDM pins when
PTC plug is used, oscillations are weak, 2.5V.
If I measure through PTC plug while using PDM plug, oscillations are also weak.

If I bend PTC clean wire, I can see small differences in oscillations.
But wire is clean. How can PTC plug be dissassembled? :shock:
Can't cut off the wire completely, I won't be able to fix it later.
Maybe something is wrong right at the plug or even inside.
Also shorting PTC pins directly doesn't help. I saw it jumped to "closed" for half a second
when flathead screwdriver tip was used (and PDM plug used).

PDM plug APPEARS to have just metal shunt. Visually everything looks fine.

 

[arnis]

After few more hours of trial and error, I understood, that PWM signal should be not, in any way, be connected to chassis.
But it was. Between PTC and PDM internal wiring. As soon as I removed plugs from aluminum frame, corrosion fell out AND
PWM distortion was gone, AND interlock was closed. Now I need to reassemble gray wire, put it all together..
About 2 volts was lost due to whatever was happening between socket and battery case.

And I will coat everything with hollow section wax (transparent-yellow anti corrosion spray liquid that turns into wax within few days).

 

[MikeinPA]

Arnis, sounds like you found the issue. Congrats on job well done!

So there was a pile of corrosion product behind the connector, which was weakening the interlock signal?

 

[arnis]

I suspect. I did not actually "fix" things. Fault just went away.


One small flake is still seen on the plastic part. I suspect this is not "just dust". It appears to be some kind of salt, likely chloride.
Metal connector is very close to that flake. And the aluminum extrusion, where socket is placed, is about 5-9mm from that
copper pin. So I suppose there was a salty path between interlock pin and battery case. That lowers PWM signal voltage and
controller does not agree with safety.
When I was wiggling plug I was actually moving metal pins inside the socket. And that changed salty resistance :mrgreen:

 

[MikeinPA]

I'd call that a fix. You traced the behavior to a specific part, and got the corrosion products away from it. You may also of headed off the failure of the fuse that protects the PTC circuit.

The part number for the aluminum casting is 29531-3NF0A.

Image of the two cables going into the back of the PTC connector:



I will be interested in seeing how you deal with this corrosion in place. More over, maybe someone can design a secondary shield that goes over the all three cables and keeps salt spray off these parts. I would buy one, or even just the .stl file.

 

[McLeafy]

Hello all,
I am having g this error on my 2013 LEAF - I sent my scanner errors to the only mechanic in town that does EV leaf’s and he said that code is “no bueno” just in Nov 2022 I paid him 2k to replace my transaxle.

Any thoughts on my errors ?

C118C 0109 ABS EV/HEV System BRC-126
Ok None ---> AIR BAG
Ok None ---> BCM
>C1A6E 0109 BRAKE EV/HEV System BR-146
>C1A70 0109 BRAKE Brake Control System BR-160
Ok None ---> CHARGER
Ok None ---> EPS
>P31E0 000B EV/HEV HV System Interlock Error EVC-300
Ok None ---> HVAC
Ok None ---> HV BATTERY
Ok None ---> IPDM E/R
Ok None ---> METER
Ok None ---> MOTOR CONTROL
Ok None ---> MULTI AV
Ok None ---> SHIFT
Ok None ---> TCU
Ok None ---> VSP
Ok None ---> AVM

Thanks

 

[Dazzi met]

I had the P31E1 000B HV System Interlock Error EVC-305 error 4 weeks ago and resolved it fairly easily. In my case, the interlock was physically broken. Here is the fix and I will add the photos shortly if I can figure out how to do so.

On the front of the battery pack are three connectors. The connector on the right goes to the PTC (there are two power wires which are the purpose of the connector). There is also an interlock circuit built into the connector which checks to make sure the connector is seated. The interlock includes a small grey wire, which my case had corroded through. See page EVB-27 of this document https://www.speakev.com/attachments/nissan-leaf-technical-manual-evb-pdf.139268/ for the interlock circuit this DTC is referring to.

A good image of a corroded grey wire https://autosphere.ca/wp-content/uploads/2022/08/batterie-haute-tension_circuit-interlock_WP-2.jpg

The wire is on top of the PTC cable and difficult to see without disconnecting the PTC cable and pulling it down. In my case I had to very closely examine the wire and did find it was completely rotted through--although the insulation was still visibly intact. I have preserved the failed wire to look at under magnification if anyone is interested. I suspect the plastic insulation is defective somehow, and cracks where it was stressed during installation.

So,

>>>disconnect the 12 V

>>>drop the front splash shield (first of three shields on the battery--not the one under the motor)

>>>put on your HV gloves, pull the safety disconnect between the rear seats. Be patient with figuring out the safety disconnect, there is a latch under the latch that needs to be tickled before the handle will swing up freely. It feels stuck somehow, but there is a hidden latch.

>>>Under the car, pull the PTC connector off, and check that grey wire very carefully. See page EVB-183 of this document to work the latch on the PTC connector https://www.speakev.com/attachments/nissan-leaf-technical-manual-evb-pdf.139268/ Use a bright light and wear safety glasses. Road grit is going to fall off that connector and right into your Mark 1s.

I shortened the grey wire to remove the damage, soldered it, and heat-shrinked it. The only tricky part is grasping the stubs of grey wire in order to use the wire strippers. I used a pair of needle nose pliers with tapes on the jaws to gently but firmly grasp the grey wire while stripping it--this way no stress is placed on the part of the grey wire going into the connector. Use marine heat shrink and protect the rest of the cable with numinum foil before applying heat. Tape the shortened grey wire down to the connector shell. Reconnect everything, codes could now be cleared.

If the grey wire fails closer to the connector, then it will likely be necessary to de-pin and install a new interlock wire. Or, perhaps, de-pin the power conductors and use a new connector.

Mods, please update the OP's title to read "P31E1 000B HV System Interlock Error EVC-305--2013, 2014--no start"

Who can do this repair to leaf?

 

[Dazzi met]

Can anyone help to repair p3e1 he system interlock error

 

[Dazzi met]

I had the P31E1 000B HV System Interlock Error EVC-305 error 4 weeks ago and resolved it fairly easily. In my case, the interlock was physically broken. Here is the fix and I will add the photos shortly if I can figure out how to do so.

On the front of the battery pack are three connectors. The connector on the right goes to the PTC (there are two power wires which are the purpose of the connector). There is also an interlock circuit built into the connector which checks to make sure the connector is seated. The interlock includes a small grey wire, which my case had corroded through. See page EVB-27 of this document https://www.speakev.com/attachments/nissan-leaf-technical-manual-evb-pdf.139268/ for the interlock circuit this DTC is referring to.

A good image of a corroded grey wire https://autosphere.ca/wp-content/uploads/2022/08/batterie-haute-tension_circuit-interlock_WP-2.jpg

The wire is on top of the PTC cable and difficult to see without disconnecting the PTC cable and pulling it down. In my case I had to very closely examine the wire and did find it was completely rotted through--although the insulation was still visibly intact. I have preserved the failed wire to look at under magnification if anyone is interested. I suspect the plastic insulation is defective somehow, and cracks where it was stressed during installation.

So,

>>>disconnect the 12 V

>>>drop the front splash shield (first of three shields on the battery--not the one under the motor)

>>>put on your HV gloves, pull the safety disconnect between the rear seats. Be patient with figuring out the safety disconnect, there is a latch under the latch that needs to be tickled before the handle will swing up freely. It feels stuck somehow, but there is a hidden latch.

>>>Under the car, pull the PTC connector off, and check that grey wire very carefully. See page EVB-183 of this document to work the latch on the PTC connector https://www.speakev.com/attachments/nissan-leaf-technical-manual-evb-pdf.139268/ Use a bright light and wear safety glasses. Road grit is going to fall off that connector and right into your Mark 1s.

I shortened the grey wire to remove the damage, soldered it, and heat-shrinked it. The only tricky part is grasping the stubs of grey wire in order to use the wire strippers. I used a pair of needle nose pliers with tapes on the jaws to gently but firmly grasp the grey wire while stripping it--this way no stress is placed on the part of the grey wire going into the connector. Use marine heat shrink and protect the rest of the cable with numinum foil before applying heat. Tape the shortened grey wire down to the connector shell. Reconnect everything, codes could now be cleared.

If the grey wire fails closer to the connector, then it will likely be necessary to de-pin and install a new interlock wire. Or, perhaps, de-pin the power conductors and use a new connector.

Mods, please update the OP's title to read "P31E1 000B HV System Interlock Error EVC-305--2013, 2014--no start"

Who can fix this problem I can’t find anybody to do this task

 

[Dazzi met]

I suspect. I did not actually "fix" things. Fault just went away.


One small flake is still seen on the plastic part. I suspect this is not "just dust". It appears to be some kind of salt, likely chloride.
Metal connector is very close to that flake. And the aluminum extrusion, where socket is placed, is about 5-9mm from that
copper pin. So I suppose there was a salty path between interlock pin and battery case. That lowers PWM signal voltage and
controller does not agree with safety.
When I was wiggling plug I was actually moving metal pins inside the socket. And that changed salty resistance :mrgreen:

I have this problem no one will fix it

 

[MozzoAU]

Hi @Dazzi met . Can you advise the forum where you are located please?

 

[ACDCPhilip]

You really need Leaf Spy Pro loaded on your phone, plus a dongle, depending on your phone type ie Android or Ios.
You can then interrogate all the fault codes.

You may even be able to delete the offending code & enable it to be driven again.

Once you have all the codes it may be more obvious what the underlying problem is.

Alternatively, get a local diagnostics specialist who is familiar with the Leaf to come out to you.
Get the full fault code printout & post it here.