Help for peugeot Ion 2012 that doesn't work.

[Franco Vecchi]

update: The can-bridge works,
I filtered the voltage value of cell 6 (can id: 613) by taking that of cell 5 and was able to move the car. Last week I managed to take it for inspection and then gone to home, covering about 15 km. The car stopped often and sometimes even went into turtle mode, but little by little I reached the destination.
Monitoring the data collected with Carscanner, I saw that cells 4 and 8 also give values of 2.1V. I tried to filter these too using an algorithm that does not completely ignore their value, but I noticed that with the increase in seasonal temperature everything got significantly worse.
In the meantime, I ordered the CMU #1 board and it should arrive today. This morning I did an analysis of the data collected during the trip and I noticed something "reassuring" which is that only the voltage values of CMU #1 are incorrect, the less "reassuring" thing is that I also found some temperature values that have peaks at 200 degrees Celsius, in cell 8 (but here I will replace the card) but also in cell 12 which would be under card #2. All other temp and voltage values seems ok.
Can these temperature spikes cause problems?

 

[MickeyS70]

the less "reassuring" thing is that I also found some temperature values that have peaks at 200 degrees Celsius, in cell 8 (but here I will replace the card) but also in cell 12 which would be under card #2. All other temp and voltage values seems ok.
Can these temperature spikes cause problems?

Intermittent, high temperature readings are another known CMU fault, they are not real but the BMU doesn’t know that and may limit power (tortoise) as a result.

If this happens on CMU 2, best to replace it also, in the meantime the CAN bridge can take care of this temporarily

 

[Franco Vecchi]

Thanks @MickeyS70 . I only ordered #1, can I manage to repair board #2 in your opinion? Is there a diagram of the temperature reading part?

 

[MickeyS70]

can I manage to repair board #2 in your opinion? Is there a diagram of the temperature reading part?

There are no ‘official’ diagrams as Mitsu never envisaged for technicians to open a HV pack.

@kiev has done some schematics, tracing CMU boards but iirc not for temperature sensors:

https://myimiev.com/threads/cmu-board-notes-eprom-cell-re-numbering-can-messages.4302/

The sensors themselves are tiny, don’t think they actually fail, more likely an issue with the read-out circuit and given the intermittent nature of the problem, you can’t really test it without driving.

If I were you, I’d order a second CMU and replace both when the pack is out…

 

[Franco Vecchi]

looking the board and the good photo in the thread you linked here up, that sensors goes into a RC network and then on the left-upper pind of processor.
there are 6 sensors, and carScanner give me only temperature for even cells ad not for odd cells (it report a -49 degrees value). Now, in CAN-BAT messages, there are 6 values, as follows:

Id 611: 0 38 38 [voltage value] [voltage value]
Id 612: 37 37 0 [voltage value] [voltage value]
Id 613: 37 37 0 [voltage value] [voltage value]
Id 614: 0 0 0 [voltage value] [voltage value]

So i think that temperature values are written out by CMUs in these 6 bytes in the first 3 messages, an CarScanner (or the master BMS) remap them only for even cell.

 

[MickeyS70]

So i think that temperature values are written out by CMUs in these 6 bytes in the first 3 messages, an CarScanner (or the master BMS) remap them only for even cell.

You’re correct, there are six temperature sensors on a 8 cell CMU boards that monitor cells A,C,D,F,G,H.

The values are sent on the internal BAT-CAN the way you mentioned, but then put on the OBD bus by the BMU (using different PIDs). It’s up to the programmers of the various apps how to interpret these values.

In general, a 88 cell car provides 66 cell temperatures, however some (later) models don’t seem to transmit individual cell data on the OBD bus.