BMWHIGH1

Okay i have had my check engine light on for about a month, I got the code
p0021. Two days ago i was thinking about just reseting because i'm tired of that light looking at me. I go outside that morning and what do you know the check engine light DID NOT COME ON. I thought i was dreaming or something because i was just talking about reseting the ecu, so i turned the car off and restarted it again still no light. so two days later it comes back on. Weird! even though i didnt fix the problem from the start why would the light go off for two days and then come back on if the problem was never fixed? Is it possible that its a milfunction??

raidwolf

iTrader: (4)

your oil? about 2 weeks ago, i got p0011, p0021, and p0300. i took it to the dealer. they ran some tests and everything was fine. i told them i've been running full synthetic oil for the life of the car, but on my last oil change, i used conventional. the service mgr said that since my car was so used to operating on full syn that switching to dino caused whatever sensors to get "confused," hence the codes. they removed the codes and i switched back to full syn.

BenKruise

How many mile does you Max have on it? Also I heard that Full Synthetic oil is no better than regular conventional.

BMWHIGH1

i use regular oil and i only have 57,000 miles on my car

bwinter7

Same thing happened to me, I had a hairline crack in my gas cap, but would only let air in if turned a certain way. So some days SES (until I went to get gas) then it'd go away, back and forth. I finally bought a new gas cap lol

DasYears

i fail to see how using different oils can affect codes...when i switched from the previous owners dino to syn i didnt get codes.

sascuderi

What a bunch of bull. The sensors in our car can not tell the difference from regular and synthetic oil. Can't believe they would tell you that!!!!

Mr. Blue Sky

iTrader: (1)

Synthetic is not necessary, its mainly a waste of money. I have seen many high mileage engines do very well with just the regular conventional oil being used (200,000+ miles). it all comes down to regular maintenance

Maxima9750

I thought that once you switch to synthetic, you cannot go back and use conventional oil. I have also heard that if you are using synthetic oil, you only need to change your oil every 6k miles instead of every 3k. Can someone correct me if I'm wrong.

raidwolf

iTrader: (4)

some say "stay with what you got." others say "switch as often as you want." i don't wish to step into that debate, that can get very ugly.

with syn oil, you can go as far as 10k before fully draining (provided you keep the oil level topped off and change filters at least twice). if i knew then what i know now, i'd stick with conventional -> if i kept to a 3k OCI.

as far as mr. blue sky's comment, syn oil is a waste *if you keep changing at 3k.* i do believe that synthetics have better protection and anti-wear capabilities than conventional. but as you said, conventional oil will do just as good, provided the oil changes are done religiously every 3k. not many people today get around to do that, tho...

armor_dan

I use Amsoil in my car, I change it every 25k or one year, whatever comes first, usually a year. That switch was done from dino oil at 60k when I got the car. No issues yet.

El_PrOfE

iTrader: (4)

My service engine soon light just came on last night and I kind of freaked. I don't rag on my car and I just got it about 3 months ago. I was driving on the free way and the light just came on.

sascuderi

Got to autozone and get the code pulled for free. That's the first step in trying to find out whats wrong.

nlmaxima

iTrader: (10)

25K is a lot. How often do you change your oil filter?

DasYears

lol @ 25k. i change mine closer to 25k ft than 25k mi.

cbr_rachie

LOL playin games with ur head huh? that's funny good luck!!!

Rach

Sunfishsailboat

My, brother very meticulous in nature would agree. You should not go back to the regular oil. Also, reg oil is changed every 3k or 3 mos. Synthetic is usually 7.5k depending on the manufacturer.

SuperStasiu

iTrader: (3)

I run mobil1 5w-30 year round and ever since mile 1 on the car, i change it every 3k miles. I drive like i stole it so to me using a oil that was formulated for better protection then some regular oil makes more sense. To me waiting to 7k miles to change just cuz ur on synthetic seems crazy, that guy with the 25k changes all i gotta say is are you nut? lol I dont believe in any of that high mileage oils bs, for me 3k is god law period. Im not lazy so i dont mind the 30 minutes under the car to change oil plus i get to look around at what else might be needing replacement soon i have an 01 with around 125k miles on it still runs like a champ.

BMWHIGH1

What does this have to do with my engine light you guys are way off topic!

DasYears

this is the point: it doesnt matter what oil you have in there. if you have 4.5 qts of mt-90 or 4.5 qts of water, the sensor doesnt know the difference. it wasnt caused by the change of syn-dino

BMWHIGH1

i never changed my oil i use the same oil!!!

BMWHIGH1

And to add on to my thread now its been almost a week and the check engine light has went back off

bluefire

sounds like a gas cap is a good start also evap presure valve gets clogged sometimes.both those items would make the light go on and off . does the amount of gas have any thing to do with the light being on or off.

and for all those who say sensors know the difference in oil, keep readinf the forums ,they do not know the difference

justinny

ok this code refers to the "intake valve timing control solenoid valve" (or IVT) on bank 2 (cyl bank closest tot he front of the car) the solenoid coil probably is out of range (ohms)
if you take a mutlimeter, disconnect the harness and check the solenoid's resistance at it pins
it should read 7.0 to 7.5 ohms @ 68 deg
sometimes coils can comeback to life for a short time or the associated wiring has a defect
check for a broken wire at the plug connector for this solenoid
(im assuming this is a 3.5)
less likeley is a bad phase (camshaft) sensor on bank 2 or an issue withthe timing gate on the rear of the cam
also a bad pos sensor (crankshaft) but you would prob have both 0011(bank 1) and 0021 (bank 2) if the pos was bad
there are a few other causes but id check the solenoid and its circuit 1st
(it should be hot [12v batt voltage] when the key is turned on engine off it is grounded through a controlling transistor in the ecm at pin 9 for bank 1 and pin 8 for bank 2 [pulse width modulation])

id get a new dealer if i were you
he obviously read out the codes and stopped there (or threw the service manual over his shoulder when he couldnt understand it)
again 0011 and 0021 are IVT control issues like above
the p0300 is a code for misfires on multiple cylinders (p0301 would be misfire on cyl 1 p0302 misfire cyl2 so on and so forth)
if you have all of these codes id say it your ecm relay because the hot lead for both IVT control solenoids (bank 1 & 2) and the hot leads for ALL the coil packs are from the same wire coming from the same pin on the ecm relay
id swap out the relay and clear the codes
if that doesnt get it it might be an issue with the wiring between the ecm relay and ivt sols /spark coils or an issue with the wiring between the ecm relay and fuse block
also on this circuit is the evap purge control sol valve and a + signal to pin 31 on ecm
the most likely candidate is the ecm relay
esp is you have heavy loads in the car (like a huge amp) and a stock charging system and battery
lower voltages (like when the bass takes a nice hit on the batt) may tarnish the contacts in the relay and cause a voltage drop (resistance) across it
sometimes like all manmade things they just go bad
extreme cases they will heat up and weld themselves
i think thats what the pin 31 is for so it can see if the ecm relay is on b4 the key is but thats just a guess

its a real shame that a dealer has to cover up his inability to understand these things by blaming your oil
ive also heard that changing to synthetic then going back to natural oil can ruin your engine (rings etc) so stick with the synthetic once you have made that commitment

this is my first post lol sorry so lengthy
u guys have helped me alot in the past with the info on these forums hopefully i can help back a little

MaxBoost925

iTrader: (33)

^^^Nice post.

Yeah switching from Syn to Dino will not throw codes - dealers are tards.

raidwolf

iTrader: (4)

lots of good info in here, justin. unfortunately, i'm a n00b when it comes to wiring/electronics, so i have no idea where any of that stuff is located. i thought my codes were related to the oil because i had just done a syn->dino oil change. hence the reason i took it to the dealer. i thought it was bs too, but i know there is a thread in here somewhere of these codes related to oil, but since the forum server crashed recently, a lot of these threads aren't showing up on search. i don't have a modded sound sytem or any other type of power-hungry systems in my car. my car still drove fine with the codes on, so in the end, all i really wanted was just to have them removed.

BMWHIGH1

Well after my last post on this page the check engine light came back on for about a week. Then the follow week it went back off again, and its been off for about two weeks now!

justinny

well the ecm relay is very accessible here is a pic of it in my car (2003 se)



make sure the ecm relay is seated properly (push it in) and locked into place
i found this warning about the ecm relay and a bunch of others



so this could be the cause if the dealer has been screwin around with it in the past

bmw your problem is probably the ivt solenoid on bank 2 but have it checked 1st

if you guys are on long island id be more than happy to check it for u lol

heres a pic of mine

raidwolf

iTrader: (4)

thanks for the info justin, i'll be checking this out soon. you've been more than helpful

justinny

no problem half this stuff isnt very hard to understand or fix it just seems like it
im a technician for a mitsu forklift dealer in new york
all of our machines have emission control systems (epa mandated) that are pretty much obd2 (we have canbus machines too)
since 2004 mitsu has used nissan engines in their machines
those manuals and the maxima manual are written the exact same way and alot of the procedures are exactly the same
even the way you can have the MIL(check engine light) flash out the codes and ERASE them for free in your garage (tried it just now on mine works like a charm)
here is how to do it: (raidwolf check that relay and try to do this to double check and erase it)
http://maxima.theowensfamily.com/ecu.asp
its tough to do sometimes, you have to count out to the end of the last second (6Mississippi, 7Mississippi, next step 1Mississippi) and the timing is crucial if youre a half second off it wont work and if you have awful misical timing you probably will never get it (lol)
make sure your floor mat doesn't interfere with the pedal (listen to it/ feel it hit the pedal stops)
hold the pedal about 11 seconds to enter dtc results mode (and hold it longer than 10scds to erase any codes if they are present after they all read out)
this is for 2002 2003 models

for that p0021 id double check the wires coming out of that connector there in that pic i posted before
aside from popping the hood you dont have to do anything to get at it
see if the wire is broken
the way that harness bends and the pressure on the copper and jacket (however slight) + vibrations can break the copper and sometimes the whole wire
unplug it and check right where it enters the plastic housing (wire harness side) if it is broken off somewhat or completely or if you can bend it (easily) like the copper is broken inside

at least this can point you in the right direction if nothing else and not worry about the kind of oil youre use setting a dtc and turning on your service light
the only way that would happen is if the oil caused a mechanical breakdown in the engine and a loose part physically damaged a sensor or trigger
which would prob cause more serious symptoms than a few trouble codes
on youre next oil change have them cut the old filter open and see if you have any metal fragments in there
some drainplugs are magnetic too i forget if ours are

justinny

no problem half this stuff isnt very hard to understand or fix it just seems like it
im a technician for a mitsu forklift dealer in new york
all of our machines have emission control systems (epa mandated) that are pretty much obd2 (we have canbus machines too)
since 2004 mitsu has used nissan engines in their machines
those manuals and the maxima manual are written the exact same way and alot of the procedures are exactly the same
even the way you can have the MIL(check engine light) flash out the codes and ERASE them for free in your garage (tried it just now on mine works like a charm)
here is how to do it: (raidwolf check that relay and try to do this to double check and erase it)
http://maxima.theowensfamily.com/ecu.asp
its tough to do sometimes, you have to count out to the end of the last second (6Mississippi, 7Mississippi, next step 1Mississippi) and the timing is crucial if youre a half second off it wont work and if you have awful misical timing you probably will never get it (lol)
make sure your floor mat doesn't interfere with the pedal (listen to it/ feel it hit the pedal stops)
hold the pedal about 11 seconds to enter dtc results mode (and hold it longer than 10scds to erase any codes if they are present after they all read out)
this is for 2002 2003 models

for that p0021 id double check the wires coming out of that connector there in that pic i posted before
aside from popping the hood you dont have to do anything to get at it
see if the wire is broken
the way that harness bends and the pressure on the copper and jacket (however slight) + vibrations can break the copper and sometimes the whole wire
unplug it and check right where it enters the plastic housing (wire harness side) if it is broken off somewhat or completely or if you can bend it (easily) like the copper is broken inside

at least this can point you in the right direction if nothing else and not worry about the kind of oil youre use setting a dtc and turning on your service light
the only way that would happen is if the oil caused a mechanical breakdown in the engine and a loose part physically damaged a sensor or trigger
which would prob cause more serious symptoms than a few trouble codes
on youre next oil change have them cut the old filter open and see if you have any metal fragments in there
some drainplugs are magnetic too i forget if ours are

GBAUER

iTrader: (2)

Amsoil is designed to go that long. You change the filter, however, more often.

flxsunxchick

iTrader: (2)

Mine plays tricks on me, too. Every now and then I'll get a code stating the voltage to one of my O2 sensors is too high, then it'll go away. I'm always like, "is something really wrong?" Then I go to AutoZone, get it read, and things are fine. Hrmph.

Silly cars. They have a mind of their own sometimes.

raidwolf

iTrader: (4)

justin: coolbeans. i had the codes removed when i was at the dealer, but i'll keep that webpage in mind in case they turn on again. hopefully my experience as a bass player will help me with the pedal timing :

BMWHIGH1

Thank you I will try this today on my lunch. So far its been two weeks and I have not gotten a check engine light so hopefully if it was out of place its back in there now! Yeah i guess if it comes back on i could make the trip out there, I live in jersey so it shouldnt be to bad of a ride thanks!

perkman87

iTrader: (6)

25k

erikgeis

ECM's go bad and then give faulty codes, correct? I mean, I think the car "can" still function normally if the ECM is faulty and throw false codes?

BMWHIGH1

[QUOTE=justinny;5951986]ok this code refers to the "intake valve timing control solenoid valve" (or IVT) on bank 2 (cyl bank closest tot he front of the car) the solenoid coil probably is out of range (ohms)
if you take a mutlimeter, disconnect the harness and check the solenoid's resistance at it pins
it should read 7.0 to 7.5 ohms @ 68 deg
sometimes coils can comeback to life for a short time or the associated wiring has a defect
check for a broken wire at the plug connector for this solenoid
(im assuming this is a 3.5)
less likeley is a bad phase (camshaft) sensor on bank 2 or an issue withthe timing gate on the rear of the cam
also a bad pos sensor (crankshaft) but you would prob have both 0011(bank 1) and 0021 (bank 2) if the pos was bad
there are a few other causes but id check the solenoid and its circuit 1st
(it should be hot [12v batt voltage] when the key is turned on engine off it is grounded through a controlling transistor in the ecm at pin 9 for bank 1 and pin 8 for bank 2 [pulse width modulation])


Can you help me with this please???? jUSTINNY