# Helping neighbor with trouble codes



## Racemaster33 (Mar 23, 2011)

My neighbor just bought a 2002 Altima with a 2.5 in it. The car came from a county with no emissions testing so the previous owner didn't care that the check engine light was on. 
She has had three codes pop up and already paid a "mechanic" to correct the issues. However, all three codes still return. 
She came to me pissed, broke and needs help. Here's where I'm at right now;

The first thing I did is clear the codes (with scanner) and start from scratch. The three things she said was wrong were (in her words) bad cam sensor, mass air flow trouble code and o2 sensor code. 

She paid to have the B1 S1 oxygen sensor replaced and the cam sensor. 

Two codes came back up quickly (2 miles) for me already. The first being P0011 which is what the guy translated as a cam sensor problem. Now, if my memory serves me correctly the cam AND crank sensors should be replaced together. Can anybody verify that? Maybe the crank sensor should also be replaced??? 
I believe that the variable timing is controlled by oil pressure on these engines. If that's the case could poor oil pressure or dirty oil passages prevent enough oil pressure to advance/retard the timing properly and cause the same code? If the previous owner didnt care enough that the ck engine light was on, they probably didn't care that they were supposed to change the oil every 3k miles also.......Not grasping at straws here, just tyring to cover the options. 
The second code that popped up quickly is P0032 wich is a B1 S1 heater circuit high code. The sensor has been replaced, why is it still showing a 'voltage high' code? I can watch is switch on the scanner but not sure about the heater readings. Anybody have experience with this issue? 

The third code has not come back yet but I do remember it was some sort of MAF code. 

I'm looking for any FACTUAL info that anybody might have on these issues. I appreciate the feedback. This poor girl bought a car she cant tag and drive.


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## jdg (Aug 27, 2009)

Full disclosure: I don't own an '02 Altima, nor a 2.5L engine, nor do I have any first hand FACTUAL information about this PARTICULAR vehicle, only what I've read here and what I know about ECU's, car, engines, electronics, etc.
If "FACTUAL" information is all you want, then stop right here...And I bid you luck in your quest to find another person with EXACTLY the same problem you have and that person will give you that FACTUAL information.

Now then...
I agree with practically everything else you've posted.

Swapping out both cam and crank sensors at the same (while may be viewed by some as 'recreational maintenance') isn't a bad strategy, since a guy should half way be able to assume that new parts are good. But if one or the other is bad from the store, then, well, you know how chasing a problem goes sometimes...

VVT is controlled by oil pressure which is further controlled by a solenoid which is further controlled by the ECU. The ECU can detect whether or not the cam is moving or not...whether it can detect how far it's moving in this particular engine, I don't know. And there is a separate code for the VVT.
Any chance you could put a real oil pressure gauge on the engine and see what's what?

O2 heater - That's likely a wiring issue if the O2 sensor has been replaced. Good call on reading the O2 switching, tells you it's working. And on a cold engine, the O2 should start switching within at least a minute. If the heater is actually dead, then it'll take longer. I think "heater circuit high" basically ends up referring to a grounding problem, but not 100% sure. And it seems, from what I've read, that grounding problems are prevalent in Nissan's these days for some reason.


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