Using KET dummy connector on DCDC or jumper HVIL to regain drivability?

[howardc64]

One of failures that can disable drivability is some failure modes from the DCDC HV clients (AC comp, coolant heater, cabin heater) These failures don't have much to do with drivability other than coolant heater to enable faster driving+charging. Tesla is being ultra safety conservative @ the cost of stranding the driver. Its a shame these can leave you stranded say on a long road trip.

Just guessing but some possible failure modes that can disable HV (and therefore drivability) include

• Short between HV +- (although resistive heaters are nearly a short already. Coolant heater measures 30+ ohms)
• higher resistance build-up on the connector (behind possibly damp carpeted passenger front wheelwell on gen1 DCDC) causing battery precharge contactor sequence to fail.

Has anyone tried the KET dummy connector (pg 5 of link, not listed on current online Tesla parts list) to replace these HV clients to regain drivability? Possible to make our own HVIL jumper and just leave the HV + - pins open (and covered up somehow safely)? pg 8 of the same doc shows diag sequence with driving the car after 3 KET dummy installed (enabling HVAC rail is probably just for isolation test. Surely the inverter rail has to be on to drive haha)

If works, then can remove passenger front tire+liner, disconnect HV+12v, plugin dummy/jumper and regain drivability. Sightly more effort than fixing a flat but much better than hassling with long distance flat bed tow and wait for repair.

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Of course there is still all the HVIL switches everywhere that can fail and leave you stranded... yet another topic haha

 

[brainhouston]

well here's my take on it..
short is only a short if its to ground, in the world of disabling driving. I would think if the heater tolerance itself would fail it would just not work but still let u drive.
i don't see how high resistance would cause those errors unless each of those plugs has Interlock in it.
from quick ebay search it looks like it does.

Looking at the cables, it looks like those small pins are only part of the connector n don't run along to the component itself.
If i ever get to this part of my car i'll investigate later or if someone wants to do it, post it here please.

So, then those KET dummy connectors are probably just a short for small 2 pins n nothing for large powered ones.
You could just take broken heater/ac/etc wire n cut off/remove HV pins n make it into dummy

If all this is true, then some moisture build up on the small pins will increase resistance n disable Interlock, causing all the HV drive disable errors...

 

[howardc64]

well here's my take on it..
short is only a short if its to ground, in the world of disabling driving. I would think if the heater tolerance itself would fail it would just not work but still let u drive.
i don't see how high resistance would cause those errors unless each of those plugs has Interlock in it.
from quick ebay search it looks like it does.

View attachment 880276
View attachment 880277

Yes all 3 connectors have HVIL circuit so disconnect = HV battery contactors dead. Same as first responder's loop. There is a wiring diagram on online Tesla service manual, hard to make out but it appears 1st responder's loop is just on HVIL. Here is HVIL info

June 2013 Report.pdf (nhtsa.gov)

Looking at the cables, it looks like those small pins are only part of the connector n don't run along to the component itself.
If i ever get to this part of my car i'll investigate later or if someone wants to do it, post it here please.

So, then those KET dummy connectors are probably just a short for small 2 pins n nothing for large powered ones.
You could just take broken heater/ac/etc wire n cut off/remove HV pins n make it into dummy

Yes, the unknown is if there is anything in the dummy behind the 2 HV connectors. Likely not. And good idea on make your own.. gotta find 3x bad components haha.

If all this is true, then some moisture build up on the small pins will increase resistance n disable Interlock, causing all the HV drive disable errors...

Yeah, there are 2 suspects on that connector : HVIL or HV+- on. My reason for thinking its not HVIL in my failure is as follows

After disconnecting coolant heater plug (HV +- and HVIL both disconnected) Reconnected 12v+1st responder... no clicking noise from HV battery pack. Exactly same as disconnect 1st responder. So it would seem in case of HVIL break, HV battery doesn't bother doing precharge contractor effort. This is why I think the fault is on the HV+- line. But no way to measure and confirm of course.

I suppose regardless, cleaning these 3 connectors seems to be a good idea given where they live. I think gen2 DCDC got relocated to the "firewall" area.

 

[brainhouston]

Yes, the unknown is if there is anything in the dummy behind the 2 HV connectors. Likely not. And good idea on make your own.. gotta find 3x bad components haha.

I doubt it but maybe a resistance of some sort to match..
Question is if DC-DC checks for all those components being connected or not during start up...
You can start with just one

Yeah, there are 2 suspects on that connector : HVIL or HV+- on. My reason for thinking its not HVIL in my failure is as follows

After disconnecting coolant heater plug (HV +- and HVIL both disconnected) Reconnected 12v+1st responder... no clicking noise from HV battery pack. Exactly same as disconnect 1st responder. So it would seem in case of HVIL break, HV battery doesn't bother doing precharge contractor effort. This is why I think the fault is on the HV+- line. But no way to measure and confirm of course.

I suppose regardless, cleaning these 3 connectors seems to be a good idea given where they live. I think gen2 DCDC got relocated to the "firewall" area.

Good point, i missed that. maybe the HV +- had moisture n somehow was lowering isolation read or something...
Strange case for sure

 

[howardc64]

I doubt it but maybe a resistance of some sort to match..
Question is if DC-DC checks for all those components being connected or not during start up...

Don't know but sounds like no one gets errors on these 3 DCDC clients. Its either no cabin AC or heat, OR won't go into drive and tow to SC for fault discovery.

You can start with just one

Good point, i missed that. maybe the HV +- had moisture n somehow was lowering isolation read or something...
Strange case for sure

I believe low iso on one of HV +- lines on these DCDC clients results in no reported error. Seems they have always been found at SC with tech pulling hidden codes and/or run low iso diag procedure ( link )

 

[howardc64]

Found the KET dummy connector source for gen1 DCDC. Manufacturer communication (technical, quantity) is B2B if any EV product business is interested

KET = Korea Electric Terminal Company (LDU gear oil is also South Korean Manufacturer SKL)

The connectors appears to be this one, the 2D pdf file page CU and PROTO appears to the right match including all 3 shape keys for the PTC heater, coolant heater, and AC compressor connections

High Voltage Fuse | xEV Parts | Product | KET

 

[KalJoMoS]

Are you sure that link is correct, seems not to be working for my iOS Safari device…

 

[brainhouston]

Works fine on Android

 

[howardc64]

Are you sure that link is correct, seems not to be working for my iOS Safari device…

Link works on my iOS 16.3 iPhone 11 on safari, chrome and edge.

It’s a Korean site so maybe language settings matter on browsers?