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Volvo EC140BLC Coolant temp

Johhnycanuck ยท 2024-07-23 14:51

Hi guys, im trying to troubleshoot a coolant temp gauge that only reads one bar. Machine serial number is 13122, and it has the monitor panel with the two gauges side by side, not one above the other which i believe makes it an I-ECU application. The coolant temp gauges sweeps on power up, i have 5v at the sensor, and Ive jumped the wires at the sensor with no change at the gauge. Ive got an older version of prosis, but the schematics leave a little to be desired. My question is this....does the sensor feed the vehicle ecu, and does that use can buss to talk with the instrument ecu? Thats kinda how it looks from the schematic, but i have no twisted wires going into the monitor panel. Thanks, john

Replies7
  1. #1funwithfuel2024-07-23 15:40

    This is for your machine

  2. #2Johhnycanuck2024-07-23 15:53

    Thanks. Is the circled component a part of the VECU?

  3. #3funwithfuel2024-07-23 15:56

    That circled part is engine ecu. The twisted pair or shielded pair are CAN bus to VECU and that hangs a hard left and is shared with the IECU

  4. #4Johhnycanuck2024-07-23 15:56

    And to further that, i would assume that since the gauge sweeps on power up, and my voltage at the sensor goes from 5v open to 0v jumped, with no change on the gauge its probably a failed VECU?

  5. #5Johhnycanuck2024-07-23 15:57

    Gotcha, that makes sense. Thanks

  6. #6funwithfuel2024-07-23 16:04

    See attached for CAN bus between controllers

  7. #7Johhnycanuck2024-07-23 18:35

    Thanks again