How to Measure a Four-Wire Idle Speed Motor?

[KathrynDella]

Four-wire idle speed motor measurement method: You can use the resistance range of a multimeter to measure the resistance of the four pins separately. The resistance of the coils is generally several tens of ohms. If the measured resistance values of the two sets of coils are similar, it indicates that the idle speed motor is functioning properly. The idle speed motor, also known as a stepper motor, commonly comes in three-wire, four-wire, and six-wire configurations, with four-wire being the most common. It has two sets of coils, with the four wires connecting to the ECU and power supply, respectively. None of them should be grounded, as this could damage the ECU. The idle speed motor is used to control the idle speed of the car. If it malfunctions or is damaged, it can affect the idle operation of the car's engine, leading to issues such as difficulty starting, unstable idle speed, idle shaking, stalling at idle, or slow acceleration. Timely inspection, repair, or replacement is necessary.