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Leaf - Gen 2 PDM/OBC/charger no output power - L1/L2 charging

1811 Views 48 Replies 4 Participants Last post by  evVanagon
I'm having a problem with L1 charging all of a sudden. This vaguely coincides with the time I put dielectric grease in the J1772 port for the winter and when the temperatures started to drop.

  • 2015 nissan leaf OBC
  • 2013 24kWh battery
  • 0 to -14C temperature outside. Battery temp is always above zero (i have the battery externally heat traced).
  • Resolve EV VCU


- When this first problem started in the fall with temperatures dropping, but with the battery well above zero, I originally plugged the EVSE in overnight and the next day it dropped 40% overnight. Indicating no charge. Then noticed with my smart outlet that there was no current draw from the vehicle. Strange. So i started investigating.

What's happening is the EVSE plugs in, I have verified the light on the EVSE says charging, I have verified the OBC is getting 100V AC inside the OBC. The OBC also registering 100V AC after the black relay before going into the underside of the OBC. So i know the OBC is getting AC voltage from the house. The EVSE does not complain with any fault lights or error messages. I have tested two different EVSEs. One stock Nissan EVSE that i've used since day 1 and my OpenEVSE.com evse. Both show that they start charging but 0 Watts are being drawn from the vehicle's OBC.

  • I check LeafSpy Pro, I am seeing a 1-2A (300-600W) draw from the battery when the car wakes up by the presence of the J1772 plug being connected.
  • I have pulled apart the OBC top and bottom to check from any blown components. Nothing seems out of the ordinary.
  • The OBC is getting 100V through the EVSE properly.
  • Disconnecting the HV battery mains at the EVSE and checking the output of the OBC. I'm getting around 2-4Volts DC. This is strange.
  • I have checked the D400 (or D408?) diode and the D108 diode inside the OBC. Traced it from the control pilot circuit. They seem fine. D400 has ~11Mohms of resistance forward. And 0.542V with the multimeter's diode tester. If I jump diode D400, then the OpenEVSE.com evse will stop charging and report a Diode check error. This helps me eliminate the diode as a symptom.
  • D108 also seems to be fine and reports 0.352V in the forward direction.
  • PP pin to ground is 4.74V DC
  • CP pin to ground is 11.78M Ohms forward
  • With logging EV-CAN messages. I'm seeing 0x679 register when J1772 plugged in. 0x390 - OBC_AC_status voltage is 100V, 0x390 - OBC_Charge_Power report 0kW. I'm seeing 0x390 and OBC_Charge_Status=charging or interrupted. Ox1DB seeing LB_Current with -0.5 to -1A.
  • 12V battery is charged and tested to be good.

Other things I noticed while in there:
Also, in this investigating R8000 and R80008 seem to be shorted. And with a magnifying glass I was able to see "0" printed on the top which makes me beleive these two resistors are just "jumper" resistors in the form of a SMD component.
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Dielectric grease is non-conductive and is used to block galvanic corrosion currents. It's also used in non-moving connections...the cold weather likely made it nastier than it already is.

Suggest you either clean up every bit of residue from it or replace the connector.

Try not to get yourself killed around that connector, because you are distracted by the problem(s). Always assume a contactor/relay fault.
 

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Discussion Starter · #5 ·
Dielectric grease is non-conductive and is used to block galvanic corrosion currents. It's also used in non-moving connections...the cold weather likely made it nastier than it already is.

Suggest you either clean up every bit of residue from it or replace the connector.

Try not to get yourself killed around that connector, because you are distracted by the problem(s). Always assume a contactor/relay fault.
Just cleaned the connectors out with isopropyl alcohol and aerosol contact cleaner. Was full of dielectric grease. Let it dry and attempted again with no difference. OpenEVSE says 0.0 watts being drawn. I've made sure all 5 pins (Line, Neutral, GND, Proximity and Control Pilot) have good continuity back into the OBC.

Of course always staying safe. Always making sure mains are disconnected and no voltage present.
 

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Discussion Starter · #6 ·

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Discussion Starter · #7 ·
From what i've gathered as important. There probably is a bunch of stuff im overlooking and i'm not sure if this is a hardware problem in the OBC (onboard charger) that is making it not possible to supply any current as shown in the (OBC_Maximum_Charge_Power_Out=0kW) OR a signalling problem in the LBC (lithium battery charger) where the LBC isn't asking for any charging power from the OBC. The latter doesn't seem to be the case because LB_Max_Power_For_Charger slowly rises to 22.7kW and the OBC_charge_power and OBC_maximum_charge_power_out still remains at 0kW

SOC is ~10%
182477198 - 0x679 - J1772 plug inserted
182527365 - 0x390 - OBC_Status_AC_Voltage = No signal & OBC_Charge_Power = 0kW & OBC_Maximum_Charge_Power_out = 6kW & OBC_Charge_Status = 0
182627499 - 0x390 - OBC_Status_AC_Voltage = No signal & OBC_Charge_Power = 0kW & OBC_Maximum_Charge_Power_out = 6kW & OBC_Charge_Status = Finished
182727599 - 0x390 - OBC_Status_AC_Voltage = No signal & OBC_Charge_Power = 0kW & OBC_Maximum_Charge_Power_out = 0kW & OBC_Charge_Status = Charging or interrupted

182863873 - 0x1DB - Total voltage=511.5V & LB_Current=511.5A & LB_inter_lock=Not interlock connected & LB_MainRelayOn_flag = No-permission
182864133 - 0x1DC - LB_Max_Power_For_Charger = 92.3kW
182873885 - 0x1DB - Total voltage = 511.5V & LB_Current = -1.5A
182884122 - 0x1DC - LB_Max_Power_For_Charger = 0kW
183123940 - 0x1DB - Total voltage still = 511.5A & LB_current = -1A & LB_Inter_lock = interlock connected
183474016 - 0x1DB - Total voltage drops to 350V & LB_Current is still -1.5A

183534267 - 0x1DC - LB_Max_Power_For_Charger = 0.1kW
183584043 - 0x1DC - LB_Max_Power_For_Charger = 0.2kW
183974358 - 0x1DC - LB_Max_Power_For_Charger = 1.0kW
184529969 - 0x390 - OBC_Status_AC_Voltage = 100V & OBC_Charge_Power = 0kW & OBC_Maximum_Charge_Power_out = 0kW & OBC_Charge_Status = Charging or interrupted
185154952 - 0x1DC - LB_Max_Power_For_Charger = 3.3kW
185154734 - 0x1DB - Total voltage drops to 350V & LB_Current = -1.0A
0x1DC - LB_Max_Power_For_Charger slowly rises to 22.7kW
 

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total volts reading 511 is a problem; how can it read such a higher voltage than the pack?

182863873 - 0x1DB - Total voltage=511.5V & LB_Current=[51] [-]1.5A & LB_inter_lock=Not interlock connected & LB_MainRelayOn_flag = No-permission

What could be intemittent with the interlock? Dielectric grease get into any HV connector contacts?

Can you wire up to use 240vac (Level 2)? Maybe the 100 vac level 1 is too low for the OBC to turn On.
 

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Discussion Starter · #9 ·
What could be intemittent with the interlock? Dielectric grease get into any HV connector contacts?
No grease in the HV connectors. Just the J1772 port. It seems like it's only registered as not connected right after the J1772 plug is inserted and reverts. Not intermittent after that.

Can you wire up to use 240vac (Level 2)? Maybe the 100 vac level 1 is too low for the OBC to turn On.
I can try that. With 10% SOC left not really possible to move, but with the OpenEVSE I can run a extension line from the stove. I was seeing 106VAC last night and no difference.
 

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Are you sure a ground fault is not being detectedby the EVSE? You did say, "old house"...most of which have no ground at all. That will stop charging in its tracks. As will a broken or non-existent ground in the receptacle/cord you are using.

I'd rig up a three wire extension cord and feed it right from the panel with a patch cord, including connecting to the ground there, since you are immobilized and can't drive to someone's place from your Frankenstein castle.

This is dangerous if you are clueless about electrician stuff, so hire one if you can't do it.
 

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Discussion Starter · #11 ·
Are you sure a ground fault is not being detectedby the EVSE? You did say, "old house"...most of which have no ground at all. That will stop charging in its tracks. As will a broken or non-existent ground in the receptacle/cord you are using.
No this is not a problem. The outlet i'm using is 3-wire and grounded. I have been charging from the same outlet since September without issue. I have seen a ground fault with a different outlet and the Nissan EVSE would just blink ready or constantly click. In this case now, the ready light is solid, plug in the connector, relays click, charge light comes on steady and stays on as if the car is charging. Same with the OpenEVSE which has a display that shows 0.0A and 0kWh.
 

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i think there is a thread about the details of the Gen 2 OBC.

If you are reading the 243vac at the little blue bubble above the 5VDC, then this indicates that the AC Input section is working, the fuse, EMI filter, precharge resistors and AC relay would be ok. Also the command to turn ON the relay from the control board was working, so the I/O signals thru CN100 are probably okay.

With the power OFF you would measure about 10 Ohms from the AC input Neutral over to the blue bubble, this is thru the precharge pair of ceramic resistors, one of which may have an internal fuse.

From the 243vac bubble the ac needs to get rectified thru a diode bridge, then it goes thru a switching PFC boost section to create a high voltage DC buss.

This then gets switched thru an H-bridge into a boost transformer to get even higher voltage that can be rectified and filtered in the HV Output stage, which feeds back to the pack.

Check that 30A fuse near the pack, plus check all the fuses you can see.

The OBC is smart enough to know when it has issues and stores fault codes, then send notice to the vehicle control unit that issues DTCs and warning indicator lamps.

If you could get the DTCs it would tell you exactly where the fault occurs.
 

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Discussion Starter · #14 ·
i think there is a thread about the details of the Gen 2 OBC.
Im having a hard time finding this thread.

Check that 30A fuse near the pack, plus check all the fuses you can see.
Which exact fuse are you referring to? The one near the pack HV PDM wires. I've checked all visible fuses on top of the charger and all have continuity. Meaning all the ones visible in the posted pictures above. The 30A fuse I think you're referring to is the one in the top-left of the picture. In the belly of the charger I found no fuses.

With the power OFF you would measure about 10 Ohms from the AC input Neutral over to the blue bubble, this is thru the precharge pair of ceramic resistors, one of which may have an internal fuse.
With power off, I just measured this to be ~7.43-8.43 MegaOhms. This seems like a problem. Going to find the source of this resistance and I'll report back. What components are support to be 10 Ohms. Where did you get this from? If it has a fuse ill try and isolate it.
 

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Discussion Starter · #15 ·
I think I found this ceramic resistor. Shindengen - Part# 50JCB 80 - B0142
Resistances I have between these pins. Pin 1 to the left.

Pin 1-2 = 3.39MOhms
Pin 1-3 = 3.39MOhms
Pin 1-4 = 8.17MOhms
Pin 2-4 - ~5MOhms
Pin 2-3 = 49.7kOhms
Pin 3-4 - 3.39MOhms
 

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The 2 tall ceramic tombstone resistors are for the precharge circuit that bypasses the black AC relay. On previous version they were ~5 Ohms each; looks like they are a bit higher now, so the total is about 17 Ohms.

But if you were getting the 243vac over to the blue blob, then the precharge and relay were working okay. The AC input is getting turned ON.

i think the shindingen is the bridge rectifier to convert the AC input to DC,
Rectangle Font Parallel Musical instrument accessory Circuit component


You would need to use the diode check function on your meter to test a diode, see the pinout in the photo.

i can't find the thread with the PDM/OBC teardown showing the boards, but this one is good

Stand alone OBC/PDModule EV system Can 2015 - SOLVED

 

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Discussion Starter · #18 ·
You would need to use the diode check function on your meter to test a diode, see the pinout in the photo.
Yup the bridge rectifier checks out with forward biased voltage across each diode as 0.450V and successfully blocks in reverse. No issues here and not diving any further into this precharge circuitry.


I'm currently trying to cross reference @muxs successfull L1/L2 CAN bus charging log he posted in this thread on page 3: Stand alone OBC/PDModule EV system Can 2015 - SOLVED - Page 3 - My Nissan Leaf Forum
 

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Discussion Starter · #19 · (Edited)
Some highlights between the EV Can log I posted above and mux's from the pastebin off page 3.

0x1DA = MG_InputVoltage is 344 but 0x1DB - LB_Total_Voltage is 344.5 whereas mux's MG_InputVoltage is 380V and 0x1DB - LB_Total_Voltage is 378V

Another glaring difference:
0x1DB - LB_MainRelayOn_flag is always "No-permission" in my logs and in mux's it is "Main Relay On Permission". This is interesting because I can put the engine in D and get power to the wheels.

Another:
0x1DB - LB_Current is equal to -1A for me and mux's shows +2A

Another:
0x5BC - LB_output_power_limit_reason is "Capacity Drop" in my log and "Normal" in mux's


Some of the similarities:
0x1D4 - Relay_Plus_Output_Status for both of us is "Main Replay Plus ON" and
0x1D4 - StatusOfHighVoltagePowerSupply for both of us is "High Voltage Supplied"
0x1D4 - ChargeStatus is both "Charging"
0x1F2 - CommandedChargePower for both of us is always 100
0x1F2 - TargetCharge_SOC is 100%
0x1F2 - Charge_StatusTransitionRequest is "Normal Charge"
0x1DB - LB_Inter_lock is "Inter lock connected"
0x1DC - LB_Charge_Power_Limit is ~22kW for both
0x1DC - LB_Max_Power_For_Charger is 21.7kW for mine and 17.7kW in mux's. Mine ramps up from 0kW to 21.8kW
0x1DB - LB_Full_charge_Flag is both "0"
0x1DB - LB_Failsafe_Status is both "Normal Start Request"
0x1DB - LB_relay_Cut_Request is "No-request"
 

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Discussion Starter · #20 ·
Attached the 240VAC L2 charge sequence. There is 4 charge sessions logged in this file as denoted by the 0x679 messages. The first session had the OBC cover off probably setting an interlock flag somewhere.

Regardless: I'm still seeing
0x1DB - LB_Current is equal to -0.5A to -2A
0x5BC - LB_output_power_limit_reason is "Capacity Drop"
0x1DB - LB_MainRelayOn_flag is always "No-permission" in my logs and in mux's it is "Main Relay On Permission". This is interesting because I can put the engine in D and get power to the wheels.
0x1DC - LB_Max_Power_for_charger - slowly climbs from 0kW to 25kW
 

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