HOW TO: Acura ECM/PCM Idle Relearn Procedure

HOW TO: Acura ECM/PCM Idle Relearn Procedure


The idle learn procedure must be done so the ECM/PCM can learn the engine idle characteristics.

Do the idle learn procedure whenever you do any of these actions:

  • – Replace the ECM/PCM.
  • – Reset the ECM/PCM.
  • – Update the ECM/PCM.
  • – Replace or clean the throttle body.
  • – Disassemble the engine or transmission.

NOTE: Clearing DTCs with the HDS does not require you to do the idle learn procedure.


  1. Make sure all electrical items (the A/C, the audio, the lights, etc.) are off.
  2. Reset the ECM/PCM with the HDS.
  3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and wait 2 seconds.
  4. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, or until the engine coolant temperature reaches 194 °F (90 °C).
  5. Let the engine idle for about 5 minutes with the throttle fully closed.

NOTE: If the radiator fan comes on, do not include its running time in the 5 minutes.






  •  How do I reset my idle speed?
  •  How do you relearn idle?
  •  How do you reset the ECU on Acura.
  •  How long does it take for a car computer to relearn?
  •  HOW TO: Acura ECM/PCM Idle Relearn Procedure


By erwincsalarda

Hello, my name is Erwin Salarda, and I'm from the Philippines. My main interests are computers and automobiles, and I am very enthusiastic about learning new things in life. Everything on this website was lovingly created with the goal of sharing it with you.