ADEM III ECM — No CAN Signal & Power Supply Issue

[Giola]

If you lost the memory battery, you lost the programming the battery was to maintain. Simply restoring the battery won't fix that. Like replacing the battery in a watch won't set the correct time or restore previously stored alarms, you need the programmer for the board to restore the missing data.

It is also not clear that you know if any data is going into the chip. You need a logic analyzer and a functional schematic as well as a CANbus transceiver attached to the output. Unless you have a known-good unit to compare to, at best you can look for mechanical faults, such as fractured solder joints, failed capacitors, or corrosion under the chips.

Also, I think your wiring to the battery connections is doing nothing. As mentioned, if that board uses the cells in series, that requires 6V, but since you didn't trace the board, applying 6V in that way could just blow the related ICs off the board. Trace what is powered by the cells and determine which ICs are being battery backed.

So… can the batteries be programmed? ¯\_(ツ)_/¯

 

[3DDave]

The pin that has to be positive is the one you did not connect to.

If the cells are placed in parallel there is no need for the second ground wire. If they are placed in series you are only applying half the required voltage.

Just curiosity - cut off the wires with enough left to solder to and, using an Ohm meter, check the resistance between where the black wires are attached (MEASUREMENT 1) and from the red wire to the empty hole (MEASUREMENT 2)

So… can the batteries be programmed? ¯\_(ツ)_/¯

No - the persistent memory that is on the board requires the cells to retain the settings are used to program the ECM to tell it what to do. Look for a static RAM chip.

What do you imagine the cells are for? They have only a combined 360mAh of capacity when new. They aren't a power supply to what the board does.

 

[TugboatEng]

I hadn't looked at the original datasheet closely enough. I didn't realize this was a battery array. I thought it was a coin cell with a cover.

 

[Giola]

The pin that has to be positive is the one you did not connect to.

If the cells are placed in parallel there is no need for the second ground wire. If they are placed in series you are only applying half the required voltage.

Just curiosity - cut off the wires with enough left to solder to and, using an Ohm meter, check the resistance between where the black wires are attached (MEASUREMENT 1) and from the red wire to the empty hole (MEASUREMENT 2)

No - the persistent memory that is on the board requires the cells to retain the settings are used to program the ECM to tell it what to do. Look for a static RAM chip.

What do you imagine the cells are for? They have only a combined 360mAh of capacity when new. They aren't a power supply to what the board does.

To answer your curiosity, it measures 25.50 mΩ.

 

[3DDave]

There were 3 questions. You answered none of them.

I'll let others figure out what you mean.