Cyclic ideling in Park mode.

[bondmi8]

I have a 2002 1.8L Sentra GXE that ramps (the engine) automatically up and down between 1000 and 2000 rpm while it is "Park" mode (P). Please help. Thanks!

[Ramius83]

Have you had any work done recently that involved disconnecting the battery for an extended period of time? Do you have a Check Engine Light on?

It sounds like your ECM (computer) has lost its memory to the Idle Air Volume, and it needs to be reprogrammed at the dealership. It is called an Idle Air Volume Learn. This process programs the idle into the ECM so that it can control the idle parameters.

[bondmi8]

Sorry about the belated reply... Thank you for your assistance!

No the battery was never disconnected or out of power.

From your reply, how do programs burned in the ECM get lost? I thought when the power goes out, all ECM programs go back to factory default settings. In addition, can it be the "idel motor" or the "throttle body"?

Please let me know.

Thanks