sbrowne

Dan -- could really use your help. I went to the self diagnosis and checked why the ECU light was on - I got 5 long and 5 short (checked it twice). On the diagnosis it comes up as NO failure recorded/detected. Now, I've had on-going problem with this light, in it has come on 5 times and each time shows something different. First was rear O2 sensor (which I replaced). Since then have had different codes, each time checked at the dealer. Without the same code repeating, I've held back in changing anything else. Now, this time I checked it my self and I get 0505 (thanks for all the info)? Any thoughts?

Thanks in advance for your help.

Daniel B. Martin

Two possibilities come to mind.

1) The problem which caused the Engine Control Module to turn on the Check Engine Light went away, so the ECM turned the light off. Example: loose fuel filler cap which was subsequently tightened.

2) You inadvertently cleared the stored Diagnostic Trouble Codes before doing the DTC readout. Don't be embarrassed about this, you wouldn't be the first person to have made this mistake.

Does your Maxima exhibit any symptoms other than the on-again off-again Check Engine Light?

sbrowne

Dan -- you're obviously a wise man. I must had inadvertendly clear the code. The light went on again today, so i checked it tonight and got two codes -- 7long5short= EVAP Control System and 9long3short=EVAP Canister Vent Control.

Now the question -- I explained before how I had this light go on again and how at the dealer they kept saying it was something else (O2 oxygen sensor -- different one that I replaced, came on the last time, before that I did get the EVAP canister). The car itself is running fine no problems (starter I think is starting to go, so I'll get that replaced).

Could one problem be triggering all? What causes the EVAP control system and canister vent control valve to go off?

Thanks again for all your help...Sanford.

Daniel B. Martin

Please read the Sticky titled ECU Diagnostic Trouble Codes. You will find that Diagnostic Trouble Code 0705 is essentially useless but it ties in with DTC 0903 which points to a problem with the EVAP Canister Vent Control Valve. The post for DTC 0903 includes a test procedure.

Some Maxima owners reported that Nissan replaced their CVCV at no charge, even though the car was off warranty. It depends on your model year. Check with your local friendly Nissan dealer. Favorite saying: Don't Ask, Don't Get!

sbrowne

Dan -- thanks for your help. I won't be able to bring the car in for a couple weeks. Now I'm wondering if the O2 sensor i originally replaced, really needed it or not. I'll try your suggestion on the EVAP canister and see if I can get it replaced at no charge.

Thanks again for your help.
Sanford.