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.