2000 nissan maxima iacv/ecu trouble

[wolfpac2112]

Please help I have a 2000 nissan maxima and my ses light came on and started idling high it seemed to be after i cleaned my throttle body, it was a p0505 code so i replaced the iacv with a new nissan oem and the tps with oem new and still nothing so i sent the ecu to repair company who said the repaired it then I went to dealer tech said he couln't communicate with ecu so he reprogrammed it then he could communicate but said when he tried to do the learn it kept kicking him out in to the coolant temp circuit and wanted to start trouble shooting so i left and replaced my coolant temp sensor and nothing i sent ecu back to repair company they said it tested fine but replaced components just as a precoution then i took it to another dealer who did the learn and it idles fine now but the ses light is still on and keeps coming back after reset. so i did a warranty exchange on the idle air control valve per nissan tech. still can't get the light to go away any suggestions or a new ecu? no one seems to know what's going on and a ecu is not cheap. what could keep my light on?

[audtatious]

In research I noticed a number of people had sent the ECM for repair but continued to the the P0505 code even though the ECM checked out. Solution was to get a used one that had never seen the issue.

[loystock]

Did you spray directly into the Throttle Body-Valve when you cleaned it? The cleaning fluid may seep into the electronic components around the TB causing it to fail (higher than normal idle RPM).

I've had a P0505 the 2nd time I cleaned the TB of the 03Q. There was no intake/exhaust leak, running IAVL was unsatisfactory and reprogramming the ECU did not help. Fortunately for me, the car was still under warranty and the TB was replaced at Beshoff Infiniti-San Jose free of charge (inluding free diagnostics and ECU re-programming).

Nissan/Infiniti discourages consumer from cleaning the Throttle Valve-Body since they have anti-gunk coating (believe it or not, it even applies to the older Maxaimas/I30s). Removal of such coating may result in higher than normal Idle RPM. Also, cars with Drive-By-Wire have very sensitive components in the Throttle Valve Assembly that can get easily damaged during cleaning. Since that episode, I have no intention of cleaning the TBs of the 03Q and 06M (both drive-by-wire). I still clean the TB of the conventioanal I30 and 97Q every 2 years with no problem (use rag for cleaning, never spary directly into TB-Valve)