2014 Takeuchi TB240, Low Voltage Error: 1704 ?

[ChiefStone]

Hello all,
Ran into an odd issue with our 2014 TB240 over the weekend...
Operating fine and out of the blue got a warning flashing on the control panel, looked it up, and it's error code 1704, "Main power supply voltage error; Voltage low".

Machine operates fine, other than the warning buzzer going off every 5 seconds...

System voltage on the control panel reads anywhere from 3.8-5.4 during key on, doesn't matter if engine is running or not.

Meanwhile, confirmed battery voltage is 12.5 across terminals with machine off, and it is charging, with a voltage reading of 14.4-14.6 while the engine is running.

No blown fuses or any chafing that I can find on the main harness... I'm stumped. Anyone ran into this before, is there a common issue that this could be related to?

Does anyone know where the control panel picks up the voltage signal from in the harness/ecm?

Thanks all!

 

[ChiefStone]

Just a little more info...

Thanks to tool_king, and the wiring diagram, I did figure out that the controller of course uses CAN signals for all of its readings.

Checked all of the grounds that I could find and cleaned, and dielectric greased the main ECM terminals.
It is intermittent some, as when I started it two days ago, it was displaying the correct battery/system voltage, but as the machine sat and idled over the period of about 5 minutes, I watched the voltage drop on the controller back down to 3.2v-3.8v and then the alarm came back.

So frustrating and puzzling.

If anyone knows where the controller or ECM is actually getting a voltage reference for the CANBUS system, I would like to check that out next.

The alternator signal I believe ties into the ECM at terminal K66, but I'm not sure if that is where the CAN system actually picks it up, or not? It almost can't be, because when I unplug the signal wire at the rear of the Alternator, which I believe ties to the ECM at K66, the voltage on the controller display doesn't change.

Or if there are any other ideas, I'm all ears.

Thanks again,

 

[Simon C]

I personally don't use dielectric grease on too much. Often on monitor panels or big plug ins with lots of wires, over a long period of time the clamping force on the pins deminishes. I have had to tighten all the receivers for pins and problem cured. Sometimes with the grease in there, if pins are loose at all the voltage drops and something is not functioning properly anymore. Also that grease is very hard to wash out even with brakleen. That is my experience.
Simon C

 

[ChiefStone]

I personally don't use dielectric grease on too much. Often on monitor panels or big plug ins with lots of wires, over a long period of time the clamping force on the pins deminishes. I have had to tighten all the receivers for pins and problem cured. Sometimes with the grease in there, if pins are loose at all the voltage drops and something is not functioning properly anymore. Also that grease is very hard to wash out even with brakleen. That is my experience.
Simon C

Yeah, agreed, thanks.
I should have been more clear in that I didn’t apply the grease to the actual pins in the connection, only a light coating to the silicone seals around the outside of the male connectors… Mainly for easier installation and removal later, if necessary.

 

[Simon C]

I ave used some Dow Corning 111 lube on the plugs also to make easier to remove and install.
Simon C