Nissan Repair: Service Engine Soon on 1997 Mamima GLE, power door locks, superb advice

Question
The "Service Engine Soon" light came on on my 1997 Nissan GLE just after the two oil gaskets were replaced.Prior to the replacement, the service engine soon was not on. Was something done wrong while the mechanic was replacing the belts?

I am planning to take it to AutoZone to check it with the OBDII equipment. However, I have always valued your expert, objective and superb advice.
What do you think caused the light to come on? Could this be the O2 Sensor.

Second Issue. The radio, power door locks and instrumention light on the dashboard all were working. Three weeks ago, We tried to start the car with jump cables. The Terminals were mistakenly placed on wrong sides because it was dark. It was after this incident that the problem referenced above happened. The dome light comes on, the speedometer works fine, the heat comes on. The only things that do not work are the power locks, power seats and the light on the dash board.

The mechanis told me that all the fuses are fine. However, some fuses are not getting power.

Your help and advice will be highly appreciated.

Thanks for taking the time to help.

Thomas


Answer
Hi Thomas -

I apologize for the late reply. I am in Hawaii, so there is a few hours -

Anyway, First answer:

From what I see, you had your belt and VC gaskets changed? I think somehow during the repair a lead got damaged to one of your sensors that report to the computer. There are many in that area of the engine. Any small glitch from over 100 sensors could turn that light on. Putting it on the diagnostic will definitely tell you what sensor it is.

Second answer:

By reversing the polarity of the vehicle, you probably burned out some fuses. Check the fuse box under your dash on the driver's side, and there is another one in the engine compartment that handles larger loads, but I think you will find blown fuses below the dash. Looks like you have a couple that blew.

I am quite sure you know how to find a blown fuse, but just in case you don't, pull each fuse out one at a time and look to see that there is continuity of metal across the terminals.

Hope this helps
calvin