Water temperature can be used on the MBE9A4i, but because this unit is designed to be simple to use, it is not a compulsory input.

The MBE water temperature input circuitry allows the use of 2 different types of sensor, either the MBE/Bosch/Nippon Denso/Lucas water temperature sensors (all use the same calibration) or Ford type which uses a completely different resistor value. This is selectable within the ECU.