OBC no output power - L1 charging

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Oct 30, 2022
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 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.
- Yes our residence's electrical panel is not balanced that well. It peaks to about 108V is the highest i've seen it. No power from the charger regardless. I have also since wired up 240VAC and no difference.

I've cross-compared a can log of my charging vs. one from a successful charge and i'm seeing a different value coming from my LBC. Can anyone lead me to why this Main Relay has no permission.

0x1DB - LB_MainRelayOn_flag = "No-Permission". whereas it should be "Main Relay ON Permission".
Note: I am always seeing No-Permission no matter if driving or charging.
The 100 vs 120 volts sounds like a major problem with your house or service entrance wiring. I would not expect the charger to work. I had a similar problem (not as bad). I called the utility and it was fixed about 20 minutes after the technician arrived. There was a corroded neutral connector on the utility's transformer.

The charger checks for a proper ground before it allows charging. This might be the problem. It might also object to the ground or neutral not being in the middle of the 240 volts.
More details following this thread: https://www.diyelectriccar.com/threads/leaf-gen-2-pdm-obc-charger-no-output-power-l1-l2-charging.208138/page-4#post-1106972
Yes I know about the 120 being low. I am also able to test on 240VAC and still no charging. And yes, there is proper grounds.
Found problem with OBC's inverter stage IGBTs. Had replace these and multiple other resisotrs and capacitors that were blown. See thread link above for details.