ECT Sending Unit Operational Test

Turn ignition switch to OFF position. Remove ECT sending unit. Warm sending unit in water. See Fig 1 . Using an ohmmeter, check resistance between ECT sending unit terminal and body. See ECT SENDING UNIT RESISTANCE SPECIFICATIONS  table. If resistance is not as specified, replace ECT sending unit. If resistance is as specified, ECT sending unit is operating properly at this time.

Fig 1: Testing ECT Sending Unit

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.