I recently have been having issues with my 95 Se 5speed. Started a few days (maybe 5) ago my brake and battery light on my dash have been on. After a few minutes of driving, however, they do turn off. I had my alternator and battery checked at advanced auto and they said that they were fine and i checked the fuse for the alternator and that too seemed to be fine. What would be the reason for these lights to come on?

Also, to add to my great week, i noticed that my car would sometimes idle at about 1500rpm. if i gave it a good throttle push to about 3-4 grand it would go down to the normal 700-800 rpm. Its not an all the time thing sometimes it idles normally and others at 1500.

Last night as i was pulling in to park i got a cel. i checked it and came up with 2 codes. 0403 (throttle position sensor) and 0707 (Rear heated O2 sensor). the throttle position sensor explains my weird idle but what is a rear heated O2 sensor? is that just my rear O2 sensor? is that just an emissions check or is that more important than that? Any info on any of these 2 codes would be great.

Do any of these issues relate to each other? Thanks

 

Are you fed spec? Rear O2 basically just makes sure that the converter is functioning properly, it just needs to see a difference in exhaust content from the upstream sensors.

What kind of voltage is the alternator pushing out?

 

I've had the same brake/batt light weirdness and my alty checked out fine on two occasions. It's still the alty, the lights go on whenever the system voltage goes to/below 10v. Changed my alty, and all is well.

 

I have a 97 Maxima SE and the brake & battery lights came on today. I have been looking through the forum and it seems the alternator may be the culprit. Any other suggestions? How much would the alternator job cost? Thanks in advance.

 

I'm not sure how many volts the alternator is pushing out... i was running late due to standing in line at advanced auto for about 45min and had to run so it never crossed my mind to ask what voltage it was pushing. probably should have asked maybe will if i check it again.

if it's the alternator i'll be pissed.. this one is a new one, i replaced it maybe 10 months ago if that.... besides paying for another part that i replaced not even a year ago, that procedure was a ***** and i am not looking forward to having to do that again. also, if its a new alternator and i'm not pushing any crazy power (amps/subs or anything to that nature) why would it go bad so quickly? how would you know for sure if its the alternator if, when tested, it reads that its working properly? i dont want to go through that whole procedure of replacing it if i'm not sure its the problem and if there is a chance in the end that it didnt fix the problem.

 

also, i checked my haynes manual on the location and procedure for replacing the TPS... i found the one located on my engine but it doesnt look like the one pictured in the manual. the one in the manual is a 2-outlet sensor, one i take it for the throttle positioning sensor and the other for the wide open throttle sensor. the one on my car is only one outlet.. the part number is Hitachi SERA483-05... why is mine different?

 

From what I've read, the 4AT Maximas were equipped with the double sensor TPS, so the TCM would know when it's wide open (I don't see why they didn't just use the TPS signal, though). 5MT's have the single sensor TPS.

Once again, just what I've read. Weird thing is that I saw a 5MT at the junkyard the other day that had an 'auto' TPS, including both plugs on the wiring harness.

 

oh ok that makes sense then, thanks for the clarification on the TPS.... sensors are an easy fix, just need purchase them then essentially unplug old and plug in new... i would still like to know if anyone has anything else to go on with the brake and battery light issue... i've searched and heynow is right that it happens when the voltage gets below 10volts... but again, its a new alternator and tested fine so how would i be sure that that is the issue? also, is it necessary or vital to replacing the rear O2 sensor? or should i just wait until i need to go for emissions? lol

 

maybe your belt tension. if its too loose then it wont turn the alternator at the right speed resulting in loss of voltage.

 

Just as pmohr said, the only purpose to the Rear O2 is to let you know if your cat is working properly, honestly if you don't change it, you will be fine. Only difference you will notice is the CEL light lit. Eventually you will need to change it for it to pass emissions.

 

Its not always the alty when the ! and batt lights come on together and go off randomly

if its the alty usually the lights stay on until the car dies, i had this issue for like over 4 months - the alternator/ac compressor harness was damaged causing the same idle problem and eventually killing my brand new alty that i replaced thinking it was the alty in the first place just like you are...id look into that if i were you

 

thanks darkman and andrei for the advice. now that i think about it that does make sense and i have had to tighten my belts for a while now after i changed to an underdrive pulley (were tight but as all belts do, they need to be re-tightened as belts tend to stretch as they "break in") the procedure is a ***** and i've been putting it off for a few months now (its not terribly bad, belts only squeal when steering wheel is turned all the way) i will tighten those as soon as i get a chance (working over 50hrs this week, gotta love semster breaks, lol) and see if that helps any.

and thanks 97SMG for confirming what i thought about the O2 sensor and just an "emissions" sensor for the most part.

if anyone else has anything to add i'm all ears, i really would love to not have to change the alternator and am willing to try other alternatives.

also, in reading the haynes manual it said that you could check how the TPS was working by checkin the voltage it was putting out with a voltage meter.. something about if it was getting over 5 volts it was ok.... i'm thinkin about waiting to replace that sensor to see if the reason that i am getting that code and it isnt working properly with my idle problems is related to the problem i am having elsewhere with the voltage throughout the car.. good idea? anyone experience this? any thoughts would be appreciated

 

I am having the same problem with the Battery and Brake light. For me in only seems to happen when it is cold outside. As the car warms up, the lights go off. I will have to check the belt tension also, guess that could be it.
Andrei, when you say Altenator and AC Harness, you talking about the electrical harness/plug. What kind of damage was done to your harness? I just want to know what to look for. I am already on my second altenator. For some reason I decided to be cheap and got my first alternator from a Junk Yard. It lasted for about a month and then went kaput. I got the second one from the local Auto Zone but just started having this problem when it got colder here in Ohio. I will have to check out my harness and belt tension.

 

well apparently it was the alternator.. 2 days ago i'm driving to work in the morning and i see that all of the lights start popping on one by one and the lights are going dim.... i've been through this before so i quickly exited the highway, as soon as i got off the off ramp, car died. AAA is a lifesavor, lol. alternator replaced, no issues anymore with the brake and battery lights. what would cause an alternator to die so quickly? is there anything i can check that would relate to that so that this new one isnt killed? i'm not running any amps/subs at the moment or any high output electronics that would draw that much power. like i said before, i replaced the alternator maybe a year ago. although it was one of those rebuilt ones from autozone or some store like that but i would imagine that they should last longer than that. i dont want to go through this again. if anyone knows something that might be related with "killing alternators" and that i could check on the car i'm all ears, lol.

 

Here's some info on the rear O2 sensor.

http://forums.maxima.org/showthread.php?t=550230

 

A mechanic fixed my problem so i did not see the wire myself or the exact location of the cut, he just said one of the power wires was knicked/almost cut and was touching something that was connected to ground (probly the frame of the car, alty housing, or something else that common)

When i hit the gas the engine would rock and the wire would move. this strained my alternator and killed it

my problem had this pattern: after the engine warms up it happened all the time for 4 months straight. until alty died and the ligths were coming on and off randomly

 

Told youse .

 

Brake+battery means you may wanna check your alternator