catalinoiu

I just had my "engine needs service soon" light on while outside was raining like crazy.
I looked on the respective thread from this forum and the ECU should have a label with "Diagnostic Test Mode Selector" but mine says something about adjusting the engine idle level (and ranges from high to low). I tried to look inside the hole and I saw a small plastic pot (which requires a star screwdriver, not flat). I did not touch anything yet because of different label.
My Maxima is 99 SE
Is this the real diag selector? I am really interested because a local shop asks for $90 to check the code with a "computer analyzer".
Thank you.

happyricefob

iTrader: (7)

first, u'll have to remove the plastic cover to get access to the ECU...

catalinoiu

Well, of course I removed the plastic cover.
The question is: the Diag Test Mode Selector **** is the same for idle adjusting?
Do I screw up anything with my idle?

fisher01

iTrader: (1)

Disregard the message concerning adjusting idle. The white plastic screw is used to obtain the ecu codes. When you look into the opening, its located downward and to the left. You need a small phillips screwdriver, like the ones used for eyeglasses, to turn the screw. Just follow the directions for getting the codes like any other 4 generation. Be carefull in turning the plastic screw, its delicate, some here on the org have turned it to hard/far and broken it off.

catalinoiu

Thanks. I've got the codes but 3 out of 4 are undefined:
3-13 undefined
5-10 undefined
7-7 Rear O2 sensor
7-8 undefined

I will try again and count the pulses.

catalinoiu

I checked them again and with the same results. Is possible that ECU gives bad (unknown) codes?

Is it possible that my Rear O2 sensor to be bad? Because I just did the smog check half hour before the light came on, and it passed with no problem.

catalinoiu

Thank you fisher...

Looks like when the smog check guy plugged the emission probe into the exhaust, it influenced the rear O2 sensor. (+the outside humidity...)
Today is warm and sunny, I reseted the ECU code and the light did not come back after driving 10 miles. Hopefully that was it.