2003 Pathfinder forgets proper idle speed P0507

[franzf11]

My 2003 Pathfinder would not start. Traced problem to faulty throttle body/IACV. Replaced with part from Nissan.(took care not to touch internal mechanism) Performed accel pedal and idle air relearn procedures and car starts and runs fine except that it idles at 1000RPM and throws 0507code(fast idle detected). Every time I do idle air relearn idle returns to specs but when I shut the truck down it "forgets" and the next time I start it the idle settles at 1000RPM once warmed up. If I do the relearn and shut it down and start it immediately it idles in spec, but if I leave it shut down for a few seconds it "forgets" and idles at 1000RPM again. I have tried unplugging the harness at the throttle body and starting from scratch, I have disconnected the battery overnight and I have checked the fuzes. Where does the memory for the idle speed reside once it is "learned"? Did I get a bad part from Nissan. I have seen similar posts to this on forums with no definitive answer. If you have the answer to this riddle I would love to hear it.

[Chuck Tribolet]

From looking at the schematics in my '01 PF FSM, it's clear that the idle air volume is remembered in the ECM. There's no
other place in the memory.

Chuck

[franzf11]

Thanks for the reply Chuck, but the 2003 V6 has an electronic throttle set-up that includes the electronic throttle control actuator, IAC, ECCS,PCM and Accelerator Pedal Position Sensor. The idle speed was correct until the electronic throttle control/throttle body failure resulting in a no start condition. This set-up is different then the set-up you refer to on the 2001 and I am wary of replacing the ECM without a definitive diagnosis. I may have to try another throttle body(it does have a "black box" riveted to it) or pay Nissan to diagnose. Thanks again.

[franzf11]

Took it to Nissan. Tech said it would remember the correct idle speed if it was reset using their "Consult II". He was right. 20 minutes and $100 later it is reset with no check engine light or abnormal idle for the last two weeks of driving.