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Ron Z.
Ron Z., - Nissan Tech -
Category: Nissan
Satisfied Customers: 18114
Experience:  18+yrs experience. State Inspector and Nissan Diagnostics
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2001 Nissan Maxima: Idle Air neccesary to replace the ECM

Resolved Question:

My 2001 Nissan Maxima needs an Idle Air Control Valve. Is it neccesary to replace the ECM?
Submitted: 5 years ago.
Category: Nissan
Expert:  Ron Z. replied 5 years ago.

Welcome to! My name is DriveFast71(Ron) and I will do my best to answer all of your questions completely and accurately.


If you are going to replace the IAC you do not need to replace the ECM as well, however, you WILL need to perform the Idle Air Volume Learn procedure.


"Idle Air Volume Learning" is an operation to learn the idle air volume that keeps each engine within the specific range. It must be performed under any of the following conditions:

  • Each time IACV-AAC valve, throttle body or ECM is replaced.
  • Idle speed or ignition timing is out of specification.


Before performing "Idle Air Volume Learning", make sure that all of the following conditions are satisfied.

Learning will be cancelled if any of the following conditions are missed for even a moment.

  • Battery voltage: More than 12.9 V (At idle)
  • Engine coolant temperature: 70 - 99 °C (158 - 210 °F)
  • PNP switch: ON
  • Electric load switch: OFF (Air conditioner, headlamp, rear window defogger)


  • Turn ignition switch "ON " and wait at least 1 second .
  • Turn ignition switch "OFF " and wait at least 10 seconds .
  • Start engine and warm it up to normal operating temperature.
  • Check that all items listed under the topic "PRE-CONDITIONING" (previously mentioned) are in good order.
  • Turn ignition switch "OFF " and wait at least 10 seconds .
  • Start the engine and let it idle for at least 30 seconds .graphic
  • Disconnect throttle position sensor harness connector (brown), then reconnect it within 5 seconds .
  • Wait 20 seconds .
  • Make sure that idle speed is within specifications.
  • Rev up the engine two or three times. Make sure that idle speed and ignition timing are within specifications
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