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Communication Problem - need reboot?

slcasner

Active Member
Supporting Member
Feb 20, 2011
1,349
909
Sunnyvale, CA
When I attempted to charge this evening, the GFCI on my original Tesla HPWC tripped. I tried my alternate charging cable, which is a Roadster Foundry variant, and that resulted in a fault as well (I think it was 934 or 936), leaving the ring showing red.

This was my first attempt to charge since the car was in for annual service last week, so it is possible that something was not left in a happy state as a result of that service. However, since the service I have also unplugged the cables from the VMS to test my adapter cable for updating the firmware on the GPS. I believe that unplugging the cables on the VMS to reset it is a valid thing to do. I did that when I attempted to do a firmware update on the GPS before taking the car in for annual service, and the car was fine after that. But I thought perhaps the cables had not reconnected completely so I should try unplugging them and plugging them back in again. I may have made a tactical error in doing that while the charge port door was still open and showing a fault. Now the VDS says "Communication problem" (1900) and shows no information in the other icons. On the dash the red plug icon is lit and in the charge port the white light is on even though the door is closed.

I tried to enter diagnostic mode, but the VDS reports back that it can't complete that operation. Is there some other reset I should do, such as resetting the VDS? I've tried opening and closing the charge port door 10 times.
 

gregd

Active Member
Dec 31, 2014
2,585
1,802
CM98
The only time I've had a "Communication Error" was when I was poking around the Diagnostic screen, looking for a place where the GSM modem status could be read. Never found it, but all of a sudden it locked up with the error. Flapping the charge port door did nothing. After some mild panic and a search here on TMC for help, I unplugged both VMS connectors and reconnected them (I forget which order I did that). That cleared the error. I expect the charge port door was open and the charger was connected at the time, but it would not have been in an error state.

I've not messed with the GSM connection since :).
 

slcasner

Active Member
Supporting Member
Feb 20, 2011
1,349
909
Sunnyvale, CA
Thanks, Greg. I had already pulled the VMS connectors twice to try to correct this problem, but I had done blue then black both times. Based on your success I decided to try reconnecting black first then blue. This did not immediately clear the problem, so I opened the trunk to see if I could see the battery disconnect, which I have not had need to see before. While looking (and not seeing it yet), I heard a couple of VDS beeps and saw that the communication problem had cleared so the icons were showing information again.

When I attempt to charge, though, I still still get faults. Looking at the list of notifictations from OVMS, I see that last night I had:

#925 DMC HW: Common Mode Sense fault
TR/1081
#1084: External Charger Problem (the GFCI tripped)
#955: DMC FW: Line Sync Loss fault
#963: DMC FW: Line Current Not Equal Request fault
#934: DMC FW: Line OverCurrent Peak fault
ditto
TR/104

Just now I got:

#955: DMC FW: Line Sync Loss fault
TR/1081

And again this tripped the GFCI.
 

gregd

Active Member
Dec 31, 2014
2,585
1,802
CM98
No ideas.

I've gotten the 104's a lot, usually on first access to the car (wake-up). Seems it's just the car being a little slow to wake up. No consequence that I can detect. I've also had a few 934s over the past few years, again without apparent issue. The 1084's have been when the charger was flaky, I believe (e.g. random J1772s on the road).

I've not had the other alerts. If the car keeps tripping the GFCI, it strongly suggests something's wrong. Switching to a non-GFCI outlet with the 120v cord might be a diagnostic, but it'd be risky...
 

X.l.r.8

Supporting Member
Supporting Member
Feb 18, 2018
1,543
969
Toronto/Miami
I would look at your charge port, make sure it’s clean, maybe an air compressor to help. Also follow the cables inside the car to the PEM, may be worth checking the fuses under the cover of the charge leads in the PEM. If it’s tripping upstream then it sounds like trouble with the grounding, either at the connections or the PEM itself.
 

PV-EV

Member
Jun 3, 2011
416
259
Alaska
Does the car drive? I assume so. Definitely check the AC input fuses in the PEM for continuity. If you have a Spare Mobile Connector, try that.
 

slcasner

Active Member
Supporting Member
Feb 20, 2011
1,349
909
Sunnyvale, CA
During the time the VDS was showing "Communication Problem" and no information in the icons, the car could not charge or drive (no surprise). After another VMS power cycle with the connectors reattached in the order blue then black, the VDS showed the expected information again and the car is drivable but charging still faults.

I agree that the AC input fuses are the first thing I would want to check. The 1.5 PEM doe not have the separate small cover over the fuse area, so it is necessary to take off the whole top cover of the PEM to access the fuses. I took the car to Tesla today for diagnosis, but if they are still bound by the rule that service techs can't open the PEM, that could result in the default "replace the PEM" diagnosis.

I did test charging with my original Tesla HPWC, with my mobile charge cable (using the Roadster Foundry circuitry), and with the 120V cable that came with the car, although with its GFCI replaced by a standard plug. All faulted.
 

PV-EV

Member
Jun 3, 2011
416
259
Alaska
I also had an issue once with charging failure that was similar to yours but I don’t recall the error codes. The red ring of death and lots of complaining. Turned out to be water in the charge port door microswitch. That took a Ranger several hours to dismantle and repair. I mention this in case you’ve been to the car wash or the drought has ended. In my case I was not getting GFI faults which leads me to believe you have one of the line fuses blown.
 

slcasner

Active Member
Supporting Member
Feb 20, 2011
1,349
909
Sunnyvale, CA
Yes, perhaps I should just have opened my PEM the same way before taking the car to Tesla service. I was the one who unscrewed the top of the PEM, using tools borrowed from the Harris Ranch crew, for the incident in that photo. I did relate that story to the service advisor and suggest the AC line fuses as a possible cause in this instance.
 

slcasner

Active Member
Supporting Member
Feb 20, 2011
1,349
909
Sunnyvale, CA
Indeed, it was one of the two FWH-150B line input fuses that blew. Tesla did not have any in stock, so the service advisor said they could order one and install it for $600 or I could take the car back to handle it elsewhere. I chose the latter. I was able to find a replacement fuse in stock at the local Grainger store and have installed it. So far I have only done a short test charging with the 120V cable on the theory that it would not be able to deliver enough current to blow the fuse again.;)
 

Roadster

JdeMO Powered
Dec 10, 2016
1,555
1,251
SoCal
Great news indeed!

In other not-so-great news... @X.l.r.8 where's the llama avatar gone?!? Granted, it's nice to see Brilliant Yellow represented but TMC is not the same without it!

72269.jpg
 
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slcasner

Active Member
Supporting Member
Feb 20, 2011
1,349
909
Sunnyvale, CA
To be prepared in case of another line input fuse blowing when I'm on a road trip somewhere, I've bought two spare fuses. Those are stored in one of the channels under the removable floor of the trunk along with a security Torx bit, a small magnetic bit handle, and an adjustable wrench that serves both to turn the Torx bit for the screws along the trailing edge of the PEM where the straight driver won't fit as well as the bolts holding the fuses. This would be easier on the 2.x PEM where only the little panel needs to be removed.

The replacement FWH-150B fuse cost $100 at Grainger, but I got two for the same price at a vendor on Amazon.
 

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