ECM/PCM Idle Learn 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 ECM/PCM.
  • Reset ECM/PCM.
  • Update ECM/PCM.
  • Replace or clean the throttle body.

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


1.Make sure all electrical items (A/C, audio, lights, etc.) are off.

2.Reset the ECM/PCM with the HDS.

3.Turn the ignition switch ON (II), and wait 2 seconds.

4.Start the engine. Hold the engine speed at 3,000 rpm (min-1) without load (in Park or neutral) until the radiator fan comes on, or until the engine coolant temperature reaches 90 °C (194 °F).

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.

6.Verify on the HDS data list that the idle learn procedure is complete.