The check engine light came on yesterday in my 94 Altima with 176K on it. I checked ecu codes and got 32 and 34. From searching this forum i gather that the 32 turned on the light and the 34 could have been there for some time.
Does anyone know if there is a component that might cause both of these codes?
If not what do i start checking to fix the problem that is causing the 32 code (egr)
If the knock sensor(s?) are bad they will prolly stay bad since I only expect to keep the car another year or so and it sounds a bit pricey/time consuming to replace them.
thanx for any help.
code 32 egr and 34 knock
there are 2 disc shaped objects about dead center on the intake manifold near your firewall. one has one vacuum line to it the other has 2 vaccum lines. the one with 2 vaccum lines on it also has a rubber hose directly under it. where that hose bends touch it and see if it is worn away. this is your bpt hose very common for them to burn up and become crispy. once a hole is burnt in it your egr no longer works because your BPT(back pressure transducer) no longer get back pressure fron the exhuast to close the bpt vent. the knock sensor code is most likely a seperate problem and is a bugger to repair since the knock sensor is tucked so far up on the block between the intake and the block. but the good news is it wont turn on the check engine light. fix your bpt and drive the car. the light should shut off as soon as the egr activates.
very small hole will be enough to cause it to throw the light. but if it is still pliable and not mushy to the tough it is probably ok. the other causes would be build up on the egr temp sensor or a restriced egr passage. the sensor has 2 wires that come out of a 14mm wrench size bolt between 2 of the intake runners. You can remove it and clean it with carb cleaner and while its out visually look in to the passage to see if there is heavy black build up. with every think assembled test the egr system by doing this. reach under the disc with one vaccum hose attached to it and push up the diaphram with your fingers. do this while the car is running at idle. the car should either die or almost die when it is pushed. this indicates the passages are clear. if it doesnt stumble at all you will need to clean the passages. if the test turns out ok again with the car idleing disconnect the hose from the egr valve and plug the hose going to the bpt into the egr(this is the other hose on the bpt that doesnt go to the egr). you may need to use an extra peice of hose to accomplish this since that hose may be to short. once you have this set up place your fingers under the egr again ,just to feel if the egr diaphram moves on its own, and rev the engine in quick short snaps. you should feel the diaphram moving up each time you snap the throttle from idle. this indicates 2 things your vaccum source is available to the bpt and the egr does operate on its own when vaccum is supplied. you can not leave it hooked up like this though cause it will cause a nasty stumble when taking off from a stop. I suspect if in fact the bpt hose is ok ,cleaning the temp sensor for the egr will resolve it.
well you can buy a very expensive socket that they offer on the snap-on,matco,mac trucks or other tool suppliers ooooooooorrrr you can do what i did and take a spare craftsman 14mm 6 point deep socket and cut a slot up the side along the flat area. works great. we have the expensive factory supplied socket in our tool bins but everybody in the shop seems to like my home made one better. it gets borrowed quite regualrly.
Hey im also having a problem with the EGR...
But i am getting no vacuum at all into the BPT valve. I followed the vacuum diagram that is posted under the hood and the tube that connects from the Intake chamber to the EGR/Canister solnoid valve is not getting any vacuum at all either.
Now i am trying to figure out how check that hose but i just cant get to that hose to check it out.
I dont wanna take off the Intake Manifold cuz im learning as i go (but i have a FSM and everything tho)...
So is there another possible way to get to that hose to check to see if there are any cracks or burns on it.
btw, this is assuming everything electrical works (like the valve and voltage cuz that is rarely the problem), i know that the EGR tube is not blocked cuz i lift up the diaphram and the engines starts to die out, Now i tested the BPT valve (according to the 240sx.org FAQ) and when i close one tube and suck air out the other, i hear air coming in from the filter that it has...is it suppose to do that or do i have to replace???
And i had a burnt out hose that give pressure to the BPT valve, i replaced that. And also i blow air in from the carbon canister and all the hoses leading to the EGR valve seem ok.
The only hose that im not to sure on is that hidden hose from the Solinoid valve to the intake...
But i am getting no vacuum at all into the BPT valve. I followed the vacuum diagram that is posted under the hood and the tube that connects from the Intake chamber to the EGR/Canister solnoid valve is not getting any vacuum at all either.
Now i am trying to figure out how check that hose but i just cant get to that hose to check it out.
I dont wanna take off the Intake Manifold cuz im learning as i go (but i have a FSM and everything tho)...
So is there another possible way to get to that hose to check to see if there are any cracks or burns on it.
btw, this is assuming everything electrical works (like the valve and voltage cuz that is rarely the problem), i know that the EGR tube is not blocked cuz i lift up the diaphram and the engines starts to die out, Now i tested the BPT valve (according to the 240sx.org FAQ) and when i close one tube and suck air out the other, i hear air coming in from the filter that it has...is it suppose to do that or do i have to replace???
And i had a burnt out hose that give pressure to the BPT valve, i replaced that. And also i blow air in from the carbon canister and all the hoses leading to the EGR valve seem ok.
The only hose that im not to sure on is that hidden hose from the Solinoid valve to the intake...
ok i did feel vacuum but not to the EGR (to the BPT yes..) so i replaced the BPT valve (which today i found out was not the problem :oface: ).
well i took it to smog and the light turned on agian during the test (even after a reset and a test drive). the mechanic told me that it could be a sensor somewhere.
...and then i realized that i did not check any sensor! (well the solinoid yes cuz there is vacuum to the EGR valve)
so which sensors should i check (maybe replace or clean?) or what else could be the problem ??? btw, the EGR temp sensor, where is it? i dont see one near the EGR valve and the FSM is no help in telling me...
well i little prob that i noticed was, when i rev the engine detecting a vacuum...i sometimes get a strong vaccum and sometime i dont = \ it could just be me but i thought id let u know.
well i took it to smog and the light turned on agian during the test (even after a reset and a test drive). the mechanic told me that it could be a sensor somewhere.
...and then i realized that i did not check any sensor! (well the solinoid yes cuz there is vacuum to the EGR valve)
so which sensors should i check (maybe replace or clean?) or what else could be the problem ??? btw, the EGR temp sensor, where is it? i dont see one near the EGR valve and the FSM is no help in telling me...
well i little prob that i noticed was, when i rev the engine detecting a vacuum...i sometimes get a strong vaccum and sometime i dont = \ it could just be me but i thought id let u know.
oh i thought that this was interesting when i came back from the shop...
On my first try...my NO read 744 (MAX 799 / AVG. 243)
On my Second Try...(with new BPT valve but everything else normal) my NO read 222 ! (MAX/AVG same as ^^). i was amazed! how could that have happened ! :thinker
i warmed up the car both times like i should have and everything was the same!
i dont get it
how ?
upon closer inspectionon on the vacuum (just right now). i revved the motor to 2k or more (maybe 3k at most) and i did feel a noticable vacuum but when the rev stayed constant, the vacuum felt weaker...[this was the hose before the BPT valve] (could it just be me !? or maybe a dirty/slightly cracked hose?). But i connected everything normally and when i rev the engine i do fell the diaphram of the EGR valve going up.
On my first try...my NO read 744 (MAX 799 / AVG. 243)
On my Second Try...(with new BPT valve but everything else normal) my NO read 222 ! (MAX/AVG same as ^^). i was amazed! how could that have happened ! :thinker
i warmed up the car both times like i should have and everything was the same!
i dont get it
how ?upon closer inspectionon on the vacuum (just right now). i revved the motor to 2k or more (maybe 3k at most) and i did feel a noticable vacuum but when the rev stayed constant, the vacuum felt weaker...[this was the hose before the BPT valve] (could it just be me !? or maybe a dirty/slightly cracked hose?). But i connected everything normally and when i rev the engine i do fell the diaphram of the EGR valve going up.
Your NOx checnged cause you made a repair to the EGR system.
When you say your first test then your second. You mean when you initially failed and then after messing with the EGR system you returned and got the second reading right?
Did you only fail this time cause your light came on but all your readings are passing now?
When you say your first test then your second. You mean when you initially failed and then after messing with the EGR system you returned and got the second reading right?
Did you only fail this time cause your light came on but all your readings are passing now?
no both times it failed because the check engine light was on. Everything passed (emissions, visual, everything!) except the CEL light. its doesnt pass just cuz its on (well it turned on both times during the test).
well i need to fix this problem just so it works (hehe my dad and I said that we should just disconnect the light from the dash so he wont see its on =D), but there is still something wrong.
I dont want to have a CEL on all the time. =(
well i need to fix this problem just so it works (hehe my dad and I said that we should just disconnect the light from the dash so he wont see its on =D), but there is still something wrong.
I dont want to have a CEL on all the time. =(
well the light does turn on when the ignition is on (bulb check) but is stays on when the car is running. the only code the ECU gives me is code 32 (EGR System).
When the mechanic was running the car (during test), the light suddenly turned on and he told the clerk that it turned on agian (because last time it did the same). So he didnt fail me due to it not working but cuz it turned on (well that it IS on).
Actually the only light that doesnt work on my dash is the Low Gas light and my clock light (clock works tho) but im gunna replace those later when i get new gauge faces.
When the mechanic was running the car (during test), the light suddenly turned on and he told the clerk that it turned on agian (because last time it did the same). So he didnt fail me due to it not working but cuz it turned on (well that it IS on).
Actually the only light that doesnt work on my dash is the Low Gas light and my clock light (clock works tho) but im gunna replace those later when i get new gauge faces.
hmm wish it wasnt that...but ok i guess i had to do it eventually.
but is there a way to take off that EGR Tube without having to take of the manifold or something ?
maybe taking off the EGR plenum and working from there ? but hmm there is a nut in the middle of the manifold that i cant get too... = \
if there is no other way, then...my car will stand still for a few days... = (
but is there a way to take off that EGR Tube without having to take of the manifold or something ?
maybe taking off the EGR plenum and working from there ? but hmm there is a nut in the middle of the manifold that i cant get too... = \
if there is no other way, then...my car will stand still for a few days... = (
i took out the EGR Temp sensor and its was at LEAST covered with about 1/16 of an inch of soot all around. i completly cleaned it up and put it back.
if the EGR temp sensor would not be working, then wouldnt the EGR throw a code 35 (EGR Temp Sensor) ? maybe it wont if it is not working to its full potential but...
and im not exactly sure how to use the voltimiter thingy and neither does my dad. Its that box with a gauge that can also check Ohms and stuff right? which mode should i set it to? (hmm...i have a circuit tester that looks like a screwdriver and tests voltage...could i use that?)
also, i cant move the car to test until tommrow (cuz my permit is expired/ gotta go to DMV), but what can i do to test the EGR when the car is running ? i tried doing what the FSM says (the test drive) and last time it did not turn on but it did during the SMOG test. hmm but i did do it while in neutral and parked...would that matter ?
oh and btw, thank you very much for the help so far Nistech u have been very patient and helpful with me. u ROCK! :ylsuper
if the EGR temp sensor would not be working, then wouldnt the EGR throw a code 35 (EGR Temp Sensor) ? maybe it wont if it is not working to its full potential but...
and im not exactly sure how to use the voltimiter thingy and neither does my dad. Its that box with a gauge that can also check Ohms and stuff right? which mode should i set it to? (hmm...i have a circuit tester that looks like a screwdriver and tests voltage...could i use that?)
also, i cant move the car to test until tommrow (cuz my permit is expired/ gotta go to DMV), but what can i do to test the EGR when the car is running ? i tried doing what the FSM says (the test drive) and last time it did not turn on but it did during the SMOG test. hmm but i did do it while in neutral and parked...would that matter ?
oh and btw, thank you very much for the help so far Nistech u have been very patient and helpful with me. u ROCK! :ylsuper
When testing voltage on any computer controlled circuit you need to use a DVOM[digital volt ohm meter] They have a high impedence to keep from frying circuits in the ECM. If your sensor was covered in soot that indicates you have a build up of carbon in the egr passage. You may need to clean it out throughly. Once you cleaned it off take it for a drive perferably up a slight incline at a steady speed of 30 mph or more. This will open the egr for the duration of the steady throttle up hill. The ECM needs to see about 20 sec of operation in a failure to turn the light on. Doing this gives it the best opertunity to come on. In the smog test during the dyno stage that is essentialy what your car is doing when it is being run on the dyno. 15 MPH with a 50% load[50% of what it takes to accelerate your car 3MPH per sec.] then 25 MPH with a 25% load. As if constantly accelerating from a stop sign or climbing a long grade.
-
myleftlung
- Posts: 3
- Joined: Sun Sep 07, 2003 8:54 am
I'm having the SAAAAAAAAAME issue; CEL came on, ECU spewed out 32. So I followed the FSM troubleshooting guide for ECU CODE 32. Checked for vaccuum, and although present it seems pretty weak. Then I looked over all the hoses, look good. Next, I pushed up on the EGR valve diaphragm and the engine stumbled. The FSM says to next check for proper voltage at terminal #105 on the ECU, which is where I am now. I went out and bought this voltmeter but was unsure of where to place the dial/positive test lead to measure the voltage. I thought you had to unplug the ECU, but realized I was wrong since you need the car running. My questions is, where exactly is terminal #105? When I compare the ECU to diagram from the FSM it doesn't look exactly the same. Thanks!