Service engine soon light on my 2008 maxima

i have a 2008 maxima with 30000+ miles. its service engine soon light came on recently. i disconnected the battery the light would go off, but would come back on again after a few days. it happened several times now. once i got a code P0011 from autozone while the light was on. the last time the light was on was a week ago and this time the light finally went off by itself yesterday. i took my car to a dealer today. a service advisor told me the reading on his code-reader is NO CODE and the car is fine!. so what have happened and what is wrong with it? could it be serious?

P0011 indicates a problem with variable valve timing

It could be a sticky solenoid or loose electrical connector to a solenoid or sensor.

hey circuitsmith,

thanks! even though the light keeps coming back on several times, but i never experienced any symptoms like hard starting, rough idle, or stalling - it runs smooth. the light finally went off by itself yesterday (i had to disconnect the battery to reset before). any insight - could it be the computer itself malfunctioning?

A loose, intermittent connection could make the light come and go.
If a problem disappears for a couple of drives the computer resets the light.

VVT is used for improved power and fuel economy. If just that function stopped working, the engine would likely still seem like it is performing ok. My 90’s Corolla – like most cars of that era – doesn’t have VVT and the engine runs fine. Most VVT systems work on actuators which rely on an electrical connection and oil pressure. So ask your mechanic to take a look-see in the valve cover area to see if there are any electrical connectors that have come loose, and double check that the crankcase oil is clean and at the “full” level on the dipstick. An oil pressure check might be considered too.

Disconnecting the battery is a waste of time. All it does is reset the ECM, which causes the ECM to redo all the initialization tests it does after reset. This can take a few hours to a few days, but eventually it will find the problem and turn the light back on again.

If the oil has been in there awhile, probably the first thing I’d do if I had this probllem is change out the old and put in new and see if that helped. It might be that one of the VVT’s actuators is clogged with dirty oil sludge.

Computer failure? I just don’t see very many complaints from Nissan owners here with ECM failures. I’d discount that unless/until the other more likely possibilities are eliminated. You may need to find a mechanic who has the Nissan-specific scan tool and experience with Nissan VVT to solve this one.