00 maxima turns off by it self

[mi_chucho]

We had problems starting up the car today. The problem looked to be the battery. The battery was dry.
Well tried to jump it, but it did not want to start at all, after several trys finally it did.
Desconnected the jumping cables and maybe 1 to 2 minutes after, the car turned off after hitting the gas pedal.
Tried to jump it again, but this time didn't have any joy. Then went to get a new battery, started smoothly at the first try, no problems. Drove back home with not a single problem.
Once at home left the car on, and desconnected the + terminal from the battery to see if the alternator was working.
The car kept on running, hit the gas and everything was looking good for about 2 to 3 min, then it went off by it self, just like that.

What could be the problem?
Is the alternator? or the comp knows that the battery is not longer connected, that's why it shuts dow by itself?
please help out here.

Thank you.

[Nahkapohjola]

Originally Posted by mi_chucho

...
Desconnected the jumping cables and maybe 1 to 2 minutes after, the car turned off after hitting the gas pedal. ...

You possibly fried your computer. Oh boy...

Maxima is NOT a T-FORD where batt cable can be taken off at will. Its a floating computer center already from -89 model.

Educate yourself by reading: http://www.cardomain.com/ride/748507/14


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DO NOT open batt while car is running, =never on computerized vehicles.

Alt should charge 13.5 or MORE to keep batt up. If not, check wiring, groundings - replace alt. See how its in 3gen http://www.cardomain.com/ride/748507/5

then seek for manual links.

[mi_chucho]

Thank you very much.
Excellent info.
Learned a lot reading "cardomain.com"
But now I have a question
If I fried the computer, what symptoms I should be looking for now, or what should I put special attention to?
I have not put a new battery on yet but I would like to be aware of what could be coming next, new situation.

Originally Posted by Nahkapohjola

You possibly fried your computer. Oh boy...

Maxima is NOT a T-FORD where batt cable can be taken off at will. Its a floating computer center already from -89 model.

Educate yourself by reading: http://www.cardomain.com/ride/748507/14


-----------------------------------------------

DO NOT open batt while car is running, =never on computerized vehicles.

Alt should charge 13.5 or MORE to keep batt up. If not, check wiring, groundings - replace alt. See how its in 3gen http://www.cardomain.com/ride/748507/5

then seek for manual links.

[Nahkapohjola]

Originally Posted by mi_chucho

... what could be coming next, new situation.

Lets hope thats not the case. The symptoms with computer glitch may be from zero to anythin... Least one fault is spike protect diodes blown on driver chips: nobody sees, feels anythin, but protection is gone. Easier blow at next spike.

I'd charge the battery, try runnin engine as usual. Measure voltage at battery, has to be constant 13.5V or more, 13.8 is healthy. If its lower, try cleaning all contacts at alt circuitry. Lastly: Replace alt...

If all seems to be ok, I'd still buy plug, terminal block and fabricate a multimeter connection to cigarette lighter: keep an eye how voltage fluctuates...

See the links at my wpage for maint manual: the 2002 manual is quite possibly about the same model u have got. Seek all info for the alt; typically theyre nogood when things fail.

Btw. Another issue with our computer centers under the hood is: never wash... Luckily maximas keep the oil slicks inside!

Btw II: If it still shuts off, that does not mean ECU is the culprit. External inputs like ign switch or their wiring is faulty, shutoff may follow. The only way is to bypass any suspected circuit with a direct jumper to +12V.

.

[mi_chucho]

Thank you very much again.
Well, I went to buy a new battery.
Definitely the old one read bad.
I brought the new one back home.
Installed in the car and all lights on the dash board came on very bright. Started the car at first try but inmediatly shuted off.
Tried again and noted, had to hold the gas pedal to keep the car alive. When I let gas go, again, car shutted off.

Hoping that, what you told me wasn't the problem, tried again and held the gas, got the rpm around 4k or a bit more, did it again few more times and all sudden it was working just like it was meant to be. It was smooth like always.

I'm still skeptical about what happened. Still don't understand the whole computerized vehicles system, but I'm learning it.


I looked at the alternator grd points, terminals, bolts and all the surrounding areas. You are right. I saw corrosion. I will treat and take care of all them parts and of course, I will do everything you suggested to give the car a longer and healthy life.

Based on your knowledge and experience, what you think would not let the car stay on for those first few minutes. Remember it shutted off by itself yesterday after I disconnected the battery.

Thank you very much again for all your help

[Nahkapohjola]

Originally Posted by mi_chucho

... what you think would not let the car stay on for those first few minutes. Remember it shutted off by itself yesterday after I disconnected the battery....

ECU uses various sensor inputs in different situations to adjust fuel injection:

While cold, O2 sensor gives no input [stupid technology]. Input has to be somehow guessed until warmup, its done by looking gas pedal position. TPS is for that. Most cars have similar potentiometer for this purpose. Yours is different location than mine, but throttle wires will guide u to throttle assy, its on that axle. To check out whattodo, clic on: http://www.cardomain.com/ride/748507/6

My guess is that all is well except alt & TPS(maybe 90$ and ½hr work). Seek detailed TPS adj info from the service manual. You may also buy/rent the nissan tester from autozone to run self diagnostics. Still make arrangements to keep tab on the alternator voltage level as the batt may not be the reason but result.