95 Nissan Maxima failed smog because the malfunction Indicator light would not go on

My 95 Nissan Maxima just failed smog because the MIL light would not come on Everything else passed. The light was working. I last noticed about 2 weeks ago after I had the car washed. I’m reading it can be a bulb or the computer? What can I expect in repair costs? I appreciate any advice.

If it’s just the lamp is burned out, couple of hundred.

If it’s because the computer has failed, a replacement computer from an auto recycler and a couple of hundred.

But that’s at my shop.


Was your battery disconnected recently? ODB mayrequire x amount of days for readings to pass.

Thank you Tester. I guess this is not unexpected for a 20 year old car. I just replaced the IA controller, Ignition switch and relay because of starting and stalling issues. I also just go the car painted. Well. at least it’s been running great and looks nice too. Thanks again

The last work that was done the car was a paint job. I’m not sure if they had to disconnect the batter or not but I’ve driven hundreds of miles since then. The check engine light did come on after I went through a car wash. I opened up the gas cap and tightened it and never saw it again. I"m not sure if that had anything to do with the light not working.

Disconnecting the battery has no effect on the function of the check engine bulb test, the check engine light should illuminate for a few second after turning the ignition to the run position.

I think barkydog was referring to the monitors on a OBDII vehicle.


Your vehicle is the OBDI engine management system.

This means it doesn’t monitor the EVAP system for malfunctions.

Here’s the how to pull codes from the computer, and what the codes mean.


And none have anything to do with the EVAP system.


Not sure if this is related, but the light on my radio hasn’t worked in months and the clock light works off and on.

Completely different from the radio.

If you do not start the engine, but turn the key to the run position, does the MIL light illuminate for a few seconds. If not, then it is likely the bulb that burned out.

Or in the long run the computer is not sending the current to the light.
This could be a wiring problem or with the computer.

But while replacing the ignition you may have inadvertently unplugged the lamp or broke a wire.


Thank you guys for your help. I apologize for my ignorance on the subject. I’m not a car person I just drive them and as of late put money into fixing them. I have the report from the smog inspection and it passed all EMS and ASM emission tests. So at least that is good. It just failed the OBD system check. Thanks again

Thanks Yosemite, the check engine light does not come on at all. I had the ignition switch and the other parts were replaced on June 25th, but I thought I saw the check engine light come on when I went through one of those unmanned car washes. Maybe I was seeing things? I am hoping it is just a light bulb and not the computer. It’s really getting hard on the pocketbook.

Did this vehicle pass inspection in the last several years or did you recently purchase the car?

I have had the car for several years now. It has had no problem passing smog. I am required to take it to Test Only Smog centers now, because of the age of the car and I live in California. I last had it smog tested two years ago.

It is possible the bulb has burned out in the last two years. It shouldn’t be too difficult to remove the instrument cluster and replace the bulb.

Thank you Nevada, I appreciate your time. I’ll be calling my mechanic soon.