Redeemed717

HI guys, thank you for taking your time to read about my troubles even if you dont have a solution for me. I have a 2002 Maxima im helping a friend repair. IT has a CEL P0051 O2 Sensor Bank 2 Sensor 1 Low Heater Circuit Malfunction.

I replaced the O2 in the car and the old O2 was melted (Ive never seen it before and havent found anybody that ever has seen it before) after i put the O2 in i reset the engine light and started the car. Without even hesitating the engine light came back on.

I then went and ohms'ed out all the wires going out from the O2 sensor (2 to the ECM and 1 to the fuse) and all of them checked out fine.

I checked power at the fuse and its there and at 11.60V without the car running. I tested the existing O2 (the new one) and it all checked out okay as well.

Does anybody have any suggestions for me? The only thing left to replace according to my diagnosing seems to be the ECM. MY friend bought the ECM already and im ready to bring the car to the dealer to have the keys reprogrammed in an hour and a half.

If there's anything else in your mind i can test before he sinks another 220 into the car on top of the 200 hes already put into it, I'm open to all suggestions and am very happy to except your criticism.

Thank you once again for your time, John

george__

iTrader: (1)

you sure you reset the ecu properly?

Redeemed717

i disconnected the battery and hit the horn/ stepped on the brakes for 15 second or so. when you firt start the car up the engine light isnt there it takes 2 or 3 seconds for it to come back on. Ive reset it like that in the past with other vehicles and its worked no problem, are these cars more fussy then that?i believe the owner had it set when they brought it to autozone to have it scanned to. the said the same thing when i talked to them

Redeemed717

I had the ECM unplugged for quite some time ( maybe 2-3 hours) when i was testing the wires off the O2, I just unplugged the positive and negative battery terminals off the car. Ill leave them off till its time to head out to the dealer, that is, unless someone else has any other suggestions that require it to be hooked up. Thanks for your constructive criticism so far though

george__

iTrader: (1)

How to reset ECU in 5th and 6th Generation Maxima's

1. Turn ignition switch on and wait about 3 seconds.

Repeat the following steps (2a and 2b) procedures quickly five times within 5 seconds.

2a. Fully depress the accelerator pedal (HARD).
2b. Fully release the accelerator pedal.

3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the CEL starts blinking. (here is where i think you can get a code from this.)
4. Fully release the accelerator pedal (while the CEL is still blinking)
5. Wait about 10 second.
6. Fully depress the accelerator pedal and keep it for more than 10 seconds.
7. Fully release the accelerator pedal (The CEL light will continue to blink).
8. Turn ignition switch to “OFF” position and now you can start the car. The CEL light should be gone.

http://forums.nicoclub.com/5th-6th-g...u-t158458.html


or just drive the car for a week or so and the light will go off by itself

Redeemed717

Wow, that sounds like a pretty serious procedure. Does that only work with Nissans?

I dropped that car off at the dealer and had the new ECM programmed for the car and it fixed the problem. Thank you for your help with everything though, its much appreciated