4jacks

iTrader: (3)

Hello,

02' Civic HX with almost 72k miles on it now..

Got my first Check Engine Light...
Went to Autozone the read the Code as
P1166 Manfacurer Contrl. Fuel Air Metering

The Thread in the sticky says the code is
P1166 Primary HO2S (No. 1) Heater System Electrical


I am at a Complete loss.

Where do I go from Here?
Can anyone better Explain this Code?
Is it safe to drive to and from work?
And most important, how to go about fixing it?

Thanks in advance !

streetglower

iTrader: (13)

actually your code is described as Air/fuel ratio sensor (Sensor 1) Heater circuit malfunction. In the OBD 2 codes thread, The first list of codes on the OBD 2 list dont seem to be acurate. you have to scroll down to the second list of OBD 2 codes in that thread. hense the reason why autozone said the code had to do with air/fuel metering, the first lists says it has to do with a o2 sensor, and then the service manaul also says it has to do with air/fuel metering.

Anyway, let me know if you have a DMM (digital multimeter) and I can give you the instructions on how to test this code. With this code, the Sensor will not be the problem. It is a circuit malfunction and either you have a faulty ECU, a bad relay, or a problem in the wiring somewhere. But once I give you the instructions on what to test, we can go from there. SO let me know if you have a DMM first.

4jacks

iTrader: (3)

*You must spread some Reputation around before giving it to streetglower again.*

I'll go buy one tommorow.. I really need one anyway.

Please post instructions, and I will respond tommorow... I'm not very good with electronics, so dummy talk please.

Thanks SG

streetglower

iTrader: (13)

ok, if you dont know much about electronics, either learn fast or have an experienced mechanic look at it. I dont take any responsibility if you mess anything up.

Now, first things first, reset the ECU. Pull the #6 fuse in the under hood fuse box for 10 seconds and reinstall it. then start the car and recheck for the code P1166. If the code doesnt come back up, you had an intermitent failure in the system. Check for loose connections at the A/F sensor and the ecm.

Now if the code comes back, Measure the voltage between ECM/PCM connecter terminals A1 and A24, 30 seconds after the ignition switch is turned on to the II position, not running. Now to figure what connecters this is, look at the row of ECU connecters and look for the one where the first wire on the top row on the left side of the connecter is green, and the 3rd one over from the left on the bottom is brown/yellow. that is the 2 wires you will be checking for voltage between. you will need to back probe the wire side of the connecter, so you will need a back probing set to efficently do this without damaging the connecter or wires. Now you can try using a small needle and sticking it in the back of the wires (We did this at school) and then connecting the meter wires to the needle to check for voltage, but a proper back probing set would be better. Just make sure if you use the needle that you dont puncture the wire, that the needle touches the terminal.

Now If you have battery voltage, update the ECU with the latest software.or substitute a known good ecu. If the problem goes away, replace the ECU. Now if there isnt battery voltage, measure the voltage between ECM/PCM connecter terminals A22 and A24. terminal 24 is the same one you did before the yellow/brown wire, but A22 is 2 terminals over from that one with a white wire.

Now I am going to stop there and if you go ahead and test this, let me know what you get up to this point. If you still havent found the problem according to what I posted, I will continue with the diagnosis. I am going slow so you dont get confused.

Now I highly recommend you take this to a mechanic because of the testing involved. If it was just testing resistance of a sensor or the voltage of a sensor, it would be different. But you are doing checks at the ECM, any mistakes can cause you to damage the ECU. But it is up to you. Let me know.

4jacks

iTrader: (3)

Reset the ECU... the Check Engine Light Came Back on After 20 seconds of Idle


Where Can I Find This Connection Terminal, Behind the Glove Box??


Thanks Again SG, I would prefer to do this myself and learn it. Even If I fudge something up this time and have to pay for it, if I learn from that mistake, it's worth it to me. I don't mind going slow at all.

Do you think the car is relatively okay to drive to and from work, while I work on figuring this out?

Also Where Can I find this Back Probing Tool?? I was going to go to home Depot for my DMM.

streetglower

iTrader: (13)

if you open the glove box, better yet, remove the glove box, you will see the ECU sitting back there on the left with several connecters coming out of it.

Now with any check engine light problem, you can still drive the car. Alot of times though when a check engine light comes on, the car will idle rough or drive rough and other times wont go over a certain speed then people have a hard time driving it. But it all depends on the problem. If the car runs fine for you, then there is nothing wrong with driving it. You wont hurt anything.

Now I am sure you can find backprobing sets from an auto store, but I am not sure. Try radioshack, I know they sell Multimeters and the accessories, but if not, try snap on or mactools or sears.

4jacks

iTrader: (3)

Cool.... I'm going to pick up a DMM today and try radio shack or Pep boys for a Back Probing set.
The car runs just fine, so I'll take my time fixing this.

Also something I don't quite understand, How did you know to eliminate the sensor as part of this error code? How did you narrow it down to either the ECU the relay or the wiring? What does the code actually mean, that the sensor is ditecting the wrong ratio of air/fuel content??

Partially the reason I ask is becuase I have a really crappy Air intake from Ebay. It's worked fine thus, far, but I haven't kept up on keeping the filter clean. didn't know if that would cause this error.

4jacks

iTrader: (3)

Does the BACK PROBING SET have a different name other than back probe ?
I tried to explain it to the Radio Shack Person to no avail...
Didn't see it on their website either!

Pep Boys was no Help Either...


Is it something that looks kinda like this???






Okay....

I went to Home Depot on Lunch and Picked up a $20 Digital Multimeter.

I'm reading over the instructions now. ... Seems pretty simple cept I don't really know too much about volts v. currents v. resistence... but I think i'll manage...

Still no luck on the Back Probe...
Do you think a Paper clip will work??

streetglower

iTrader: (13)

The air/fuel ratio sensor detects the density of the oxygen in the exhaust gas, and sends it to the ECM/PCM as an electrical current value. The current value changes in proportion to the density of oxygen. Based on these signals, the ECM/PCM controls the amount of fuel injected to regulate the air/fuel ratio. The ECM/PCM converts these signals from electric current to voltage values, and outputs them to the HDS or a scan tool. That description came from the manaul. I wasnt too sure on what the actual sensor did, but figured it had to do with the air/fuel ratio sensing.

Now when I read through the diagnostics for this code, most solutions were related to fixing wiring problems, or updating the ECM or replacing it. And the last solution if everything else was ok is to replace the A/F sensor relay. None of the solutions require the replacement of the sensor itself, so that eliminates the sensor as the problem. But once you start testing some of this, it will point you toward the problem.

Now I dont think the intake is the problem.

I dont know of any other name for the backprobing set. It Looks like this, here are some links. they slip onto the DMM test leads.

http://www.autotestsys.com/Merchant2...gory_Code=SPEC

http://buy1.snapon.com/products/diag...JPG&email=true

http://all-tool.com/BY_MASTER_CATAGO..._clamps_54.htm

http://www.muellerelectric.com/NewPr...hBackprobe.htm

Now I looked through radio shacks website and didnt find anything, but if you have a thin needle, not to thin, but not too thick, just right to backprobe a wire, then you can use it. Just try to find one that doesnt have a sharp end, that way you dont risk messing up the wire.

Now to better help you understand electronics, Current is what flows on a wire or conductor like water flowing down a river. Current flows from points of high voltage to points of low voltage on the surface of a conductor. Current is measured in amps.

Voltage is the difference in electrical potential between two points in a circuit. It's the push or pressure behind current flow through a circuit, and is measured in volts.

Resistance determines how much current will flow through a component. Resistors are used to control voltage and current levels. A very high resistance allows a small amount of current to flow. A very low resistance allows a large amount of current to flow. Resistance is measured in ohms.

Now on the DMM, not sure how yours looks, you will have 2 symbols which you can switch too which will test voltage, one is for testing DC voltage, the other is for testing AC voltage. The one you need for most car electrical testing is the DC voltage one. There should be a straight lines or lines above the V for DC volts. the AC volts one will have a squigily line above it. Dont use that one.

Now when checking for resistance, there should be a symbol that looks kinda like an upside down C. that will be your setting for checking resistance. then there is the continuity tester. Checking continuity just checks too see if there is a path or electricity to follow. I dont know how to explain this symbol, but it looks like a sound symbol.

Hope this helps you, if you have other questions, let me know.

Oh and BTW, after reading and looking through the manaul, the air/fuel ratio sensor is the O2 sensor. Different years call it by a different name.

4jacks

iTrader: (3)

Very Very Helpful...

You are the freaking Man...

I'm going to go home and look at all my needles and pins, take my glove box off.

I'm going to post pics of my glove box and the connections so i don't screw up. ...

I'll post up a pic of my DMM but what you said was right on target and the manual explains it pretty well.

More to come tonight when I get home.

4jacks

iTrader: (3)

Okay Here is my nice new multimeter $20 Home Depot



And Here is the Inside of My Glove Box Couple Shots...





So which plug is the ECM/PCM connecter terminals A1 and A24 ????

Also do you have a diagram of the different terminals... so I don't mess with the wrong ones. ???

Thanks Again..

tfnaaf

iTrader: (2)

http://www.7thgencivic.com/forums/sh...d.php?t=155306

4jacks

iTrader: (3)

You must spread some Reputation around before giving it to tfnaaf again.

It's really a shame that it's always the same people are the ones that are extremely helpful...

Are the terminals Labeled ???
Which Terminal in the Picture is Connector A ???

Thanks Guys.

tfnaaf

iTrader: (2)

Heh i forget what one, but follow streetglowers lead on what one is what connector

streetglower

iTrader: (13)

I am looking at my cars ECU to figure this out. The ECU wiring diagram that you posted, some of the colors of the wires differ from what the manaul says. maybe different cars use different colors. For instance, in the manaul for this code it says connecter A1 is a green wire, but the diagram says it is a black/white wire. Mine is a black/white wire.

Now 4jacks, look at your ECU in the glovebox and look at the ECU in the back right. there should be 3 connecters coming out of it correct? Look at the one closest to the bottom and tell me what color the first wire is on the top left of the connecter? the very first wire? Is it green or black/white?

4jacks

iTrader: (3)

Yeah... they all have different numbers of pins, so I could just count...

I just realized that something *i think*
with the back probes ... (I have two pins)
I do not have to unplug the connector do I??
I will be measuring the voltatage from the back of the connection.

I guess if I disconnected it , it would mess up when I turned the car to ON position...
Ok..
So I need both Needles right.. ?

streetglower

iTrader: (13)

Yes each one has a different number of pins, but look at the first oconnecter closet to the bottom of the ecu, and tell me the color of the first wire on the top left of the connecter? Green or black/white?

And unless the manaul specifically tells you to pull it out before turning the ignition on, then it will say to leave it in. In this case, it says to leave it in.

4jacks

iTrader: (3)

Ummm.... Red with Blue Stripe...

Uploading Pics... one sec

4jacks

iTrader: (3)

streetglower

iTrader: (13)

Well if you look at the ECU, it is standing up, and the connecters are going upwards next to each other. The farthest connecter towards the bottom is the A connecter. Next is the B connecter, then the C connecter if you have an automatic transmission, then the E connecter. The B and C connecter are small connecters. A and E are large connecters.

Now one the A connecter, your first wire on the connecter on the top row on the left should be a green wire. Different modles use different colors. Like mine is a black/white wire. You might have to move around the harness to get a good look, but dont wiggle too much. Let me know if you do find the green wire?

tfnaaf

iTrader: (2)

gray connector red blue in top left corner is connector "A"

tfnaaf

iTrader: (2)

I should have said the way the ECU sits its the top left wire is red blue

streetglower

iTrader: (13)

actually it should be on the bottom of the ECU. when you look in the glove box, the connecters are standing up next to each other. The A connecter is on the bottom closet to the floor. It is the grey connecter though.

streetglower

iTrader: (13)

I see what your saying, its kinda confusing. The A connecter is at the point where you have to wiggle it around to get to some of the terminals.

streetglower

iTrader: (13)

the wire you are looking at it the wire on the top row on the right side of the connecter, but you want the one on the left side of the connecter, the wire closest to the floor on the top row.

4jacks

iTrader: (3)

Gosh Darn it That's Confusing..
There are 3 connectors...
TOP MIDDLE AND BOTTOM
(manual trans)

the one on the bottom is Gray...
That is the A connector ?????

That is in the top picture above and the top left wire is red with a blue strip.

streetglower

iTrader: (13)

the bottom connecter closest to the floor is the A connecter. It is a grey connecter. The B, then E since you have a manaul trans.

that wire you are referring to is the wire on the right side of the connecter. That wire is in the number 9 terminal, you want the number 1 terminal. It is the first terminal/wire closest to the floor on the top of the connecter. Should be a green wire.

streetglower

iTrader: (13)

the way you are looking is different from how I am looking at it. You see where that red/blue wire is, look straight down untill you run into the last wire in that column. that is the first wire. I am looking at the terminals sideways. long ways. basically how they go 1,2,3,4,5,6,7,8,9,10
11,12,13,14,15,16
17,18,19,20,21,22,etc. I am looking at the connecters this way.

4jacks

iTrader: (3)

streetglower

iTrader: (13)

I sent you a PM. We are looking at the connecter at different angles. I see how you are looking at it. I will try and call you if possible and try and explain this better.