PTC Heater Fault causes car to not start, Power Limit flash, Red Triangle ON

[Myles Twete]

Helping a friend today with a non-driving THINK, on turning the key ON:
* no contactor activity
* Power Limit light flashes
* Red Triangle ON

CommTool shows no Faults.
However, CAN trace does show:
0x304: Highest Error = 4 (Immediate Contactors OFF)
0x305: BMS State = 15 (BMS Fault)
0x610: CCC = 43 (PTC Heater Fault)

So, pretty clearly there's a fault with the PTC Heater system.
Options?  Next Steps?  Recommendations?
This car appears to have 2 external fuses in the harness for the PTC heater.  The owner said that he checked them but...

Attached is a CAN trace.

Tusen takk for hjelper meg!

-Myles Tveita

[worry]

Hi Myles (fra Tveita). 
Try removing the heater cable from the PCU, install blind plug.

[Warlock]

Now this was a interesting TRC-file!

I seldom see (or notice?) logfiles with CAN messages from the CDCM_PTC unit (0x045). Since there is actually no CAN lines to the PTC itself this must be produced in the CDCM unit.

It states:
PTC_FuelCutOff: Terminate Fuel


Clearly it detects something, which is critical enough to deny power to the rest of the systems?
As Worry states, one can try to disconnect the PTC ans see if it helps. The PTC as an error-line to the CDCM unit via the low voltage connector, it might have triggered something. Also i read somewhere that you should not disconnect one o the plugs of the PTC without disconnecting the other (don't remember if it was HV without LV or vice versa) so just disconnect both, and use a blind-plug (for the EPO-circuit not to trip).

I'll look into he trace-file furter and see what I can find....

[Myles Twete]

Thanks Worry (and Warlock)
And it's even easier than that: it appears that someone at some point installed external fuses for the A/C and Heater, so we can just pull a fuse and leave the HV connector plugged in.  But that won't address the problem.  I mean, right now the contactors never even close to bring HV to the PCU, so it won't do anything.  The problem is that either the PTC itself is sending a Fault message to the CDCM or the CDCM is misinterpreting a fault.  Since the owner of the car had noted a "smell" in the car related to the heater before this happened, I think the PTC itself failed (perhaps a transistor on the PCB or ... ).  And so, I need to find the LV connector and disconnect that.  Also having the HV fuse removed before turning key back ON. Hopefully the CDCM will not have a problem with this and the car will once again run at least.  I just read this recent thread on FB forum, which is informative: https://www.facebook.com/groups/27279972050/permalink/10161957249352051/

[Warlock]

Also found this in the trace-file:

0x610 EDL_Data00:
Remote_Comm_Fault: 1
BMS_Contactor_Condition_Codes: 43
BMS_Highest_Error_Reason: (5) Current Limit On High Temperature _(dec)


Also the 0x720 complains about the 12V auxiliary battery is getting low voltage..

(the BMS_CCC: 43 .. which is ... one of my lists stops at 37 at least, I need to relocate the newest version of this list and modify the DBC-file to display it directly in SavvyCAN so I don't have to remember where to look up... --> TODO-list)

I haven't spotted any high temperature measurements anywhere (yet) did you also look with CommTool? Spotted anything there?


Also, it seems you have a slightly different DBC-file than I have. I use the one which is attached to SavvyCAN (and have modified it to include the BMS-file and some other error codes). Would you consider to share it?

[Warlock]

The low voltage connector should not be far from the HW connector.
It's a black "on-cable" spring-locked 4pin flat connector originally ment to connect to the top of the water-heater. Just follow the HW-line from where it goes through the torpedo-wall, the black cable there would end in a conector near your passenger side headlight somewhere.

[worry]

The red triangle was the reason I suggested removing the HV cable alltogether. There probably is a HV to ground issue somewhere?

Are you sure there is no contact from the HV plug to grund after removing those fuses?

[Myles Twete]

Thanks again guys :-)

Verified that CCC=43 translates into PTC Heater Fault.
On the HV: I did not remove any fuses yet on the car.  CommTool reported over 1200kohm isolation, so there was no isolation error reported.  It also showed no Fault Codes (Active, Latched or Historical).  All 16 RLECs also reported cell voltages that looked great, with the cell voltage spread being just 14mv across the entire pack (seen also in 0x610).  When I was at the car I didn't notice any error codes at all---it wasn't until I got home and looked carefully in SavvyCAN at the messages that I discovered the ones I noted above.  Interesting about that High Temperature Current Limiting (Highest Error = 5).  I did not notice that earlier.  Message 610 shows MaxTemp = 22degC and MinTemp = 11degC.  I should have taken snapshots of the RLEC data in CommTool...maybe there's a RLEC with a bad temperature measurement...that would not be good.  Looks like I have things to look at if I offer more assistance to this THINK owner... Tusen takk igjen min venner!

[Warlock]

Yeah, I found a later version of the list for CCC as well

Updated the DBC file to include this list, and added some clarifications for some other messages as well. Adding it here (as usual, remove .txt at the end to use)

Dropbox-link:
https://www.dropbox.com/scl/fi/jtn6il96r9ydikr2p6dtf/ThinkCity_modified7.dbc?rlkey=qlzueswr4gldyn1mbag4lem2l&dl=0

With this DBC-file one can also see that in message 0x304 <BMS_System_Data_3>:
sys_highestErrCat: (4) Category switch-off
    is "Disallow operation imidiately" for this car....

[Marsto]

Hello again Myles. Good to hear you still got some Th!inkering to do. I do have the original PTC retrofit instructions I used to rebuild the original fluid heater to a PTC heater. At least you can see how we in the European Thinks could do that job. The job was done with some CDCM reprogramming help from some of the original engineers at the Norway factory outside Oslo. Some steps in the instructions was not needed on our gen.2 car. The VCU programming described was not necessary and the we could skip adding the yellow control cable. I enclose it just in case you could draw some info from it or don`t have it at all. Ha det bra, Myles og ha en fin dag i Portland, Oregon