INSPECTION PROCEDURE 1. INSPECT ENGINE COOLANT TEMPERATURE SENSOR  (a) Partially immerse the sensor in water and warm up the water. (b) Measure the resistance according to the value(s) in the table below. Standard Resistance:
If the result is not as specified, replace the engine coolant temperature sensor. NOTICE: When checking the sensor in water, keep the terminals dry. After the check, wipe the sensor dry. HINT: If the result is as specified, do not replace the engine coolant temperature sensor. |
Toyota Tundra Service Manual > Sfi System: ECM Power Source Circuit
DESCRIPTION When the ignition switch is turned to ON, the battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil, closing the contacts of the integration relay (EFI relay) and supplying power to terminals + ...
