Granting (by info sent in priv),

Do you have ISP cable (Parport DSUB25 or USB-ISP ?) Will need to follow

If considering bootloader upgrade, (so that internal BOD can be disabled) highly recommended:

PLEASE CHECK THAT v3/10267 has reset chip at the atmega128/pin20 reset, eg

See GenBoard/VerThree/Schematic eg


Engine off, ambient sensor temp (~20C)

Hint: The output is almost certainly connected to an input with pullup (possibly strong pullup).

Sensor connection (seems good):

EGT sensor is K type yellow-red wires:

  • yellow = green (plus wire) to board GND
  • red = white (minus wire) to the board cathode on corner