p 2112 how do you know witch part is bad & best way to test Ecm or sensor or module?

Question

P 2112 How to test all items sensor or ECU or throttle body?

Answer 1

P2112 Electronic throttle control- unable to open

When you first turn the key on ,the PCM test the throttle plates before starting the engine , by opening the plates,when it does not open you get DTC code P2112. To determine if it is the PCM or throttle motor you test for voltage at the throttle motor, Remove the air cleaner and check the throttle body with your hand, manually open the throttle blades it should move smoothly.If it does not you can bet it is binding. When you check for voltage and there is voltage it is the throttle body motor being non op.You measure for 5 volt supply.