Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 62Get this manual
IGNITION
Temperature Sensor
Two (2) temperature sensors are used to provide cylinder head temperature information to the ECMOne sensor is mounted in the starboard cylinder head and one in the air compressor cylinder headThe ECM uses this information to increase injector pulse width for cold starts and to retard timing in the event of an over-heat conditionAn ohms test of the temperature sensor would be as follows: Insert digital or analog ohmmeter test leads into both TANBLACK sensor leadsWith engine at temperature (F_) indicated, ohm readings should be as indicated 10270 255 240 225 210 195 180 165 150 135 120 105 90 75 60 45 30 15 0