Two ECUs, 6 different CELs!
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Re: Two ECUs, 6 different CELs!
I dont know how to check continuity. But from what I sorta understand, I'm going to need some really long tester leads from my meter to reach from the sensor to the ECU harness, no?
Wouldn't checking the voltage at the signal wire for the MAP sensor at the ECU and the sEnsor itself show continuity?
FWIW, I tried the P72 ECU just now. It stalls the car out and runs really bad
Wouldn't checking the voltage at the signal wire for the MAP sensor at the ECU and the sEnsor itself show continuity?
FWIW, I tried the P72 ECU just now. It stalls the car out and runs really bad
Last edited by PreClude; Jun 1, 2011 at 07:02 PM. Reason: Nsor n
Re: Two ECUs, 6 different CELs!
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Re: Two ECUs, 6 different CELs!
The video you provided shows a code 3 and code 21.
Map sensor and vtec spool solenoid.
As mentioned via email. You need to check the continuity between the map sensor signal wire at the map sensor and the map sensor signal pin at the ecu.
You also need to perform a continuity test on on the vtec solenoid wire from the solenoid to the vtec solenoid pin on the ecu.
A clogged cat wouldn't cause a code 3 or code 21.
Map sensor and vtec spool solenoid.
As mentioned via email. You need to check the continuity between the map sensor signal wire at the map sensor and the map sensor signal pin at the ecu.
You also need to perform a continuity test on on the vtec solenoid wire from the solenoid to the vtec solenoid pin on the ecu.
A clogged cat wouldn't cause a code 3 or code 21.
I will check continuity tomorrow if I can figure out how to do it. Do I have to disconnect the battery? Do I keep the battery connected and have the key on, engine off? Or do I do all of this testing with the engine on and running? Do I unplug the connections at the sensors, or do I backprobe the wires like I did for the MAP sensor voltages?
On the ECU side of things, do the same things apply? Do I disconnect the harness and put the tester leads of the meter in the pinout locations for the MAP and VTEC sensors I will be checking? Does the power wire go to the sensor signal and the ground wire go to the ground wire on the pinouts? Or just to a local engine ground? I put the meter selection on the OHM setting right? What reading am I looking for.... 0? Or does the meter beep or something when I have continuity? And I DO want the continuity, right? If I don't have it, what could that indicate?
Sorry, I'm just confused on how to check continuity exactly.
Fair enough. But I don't understand how the ITR ECU that was never even remotely intended to run my car runs it better than the chipped P72 that is supposed to be tuned properly for my H22A4 engine etc.... You would think it would get closer and closer to running better on the P72 as I go about fixing these various codes, right? But it seems to go more in the direction of running better on the P73 as I fix these codes...
Re: Two ECUs, 6 different CELs!
Good deal, so I don't need to go drop $300 on a new cat lol. I'll wait until I get everything else fixed first. Sometimes I forget why I bought a Honda. I thought I was trying to save money in the long run. I sure hope this pays out. Right now the outlook is grim to say the least
I will check continuity tomorrow if I can figure out how to do it. Do I have to disconnect the battery? Do I keep the battery connected and have the key on, engine off? Or do I do all of this testing with the engine on and running? Do I unplug the connections at the sensors, or do I backprobe the wires like I did for the MAP sensor voltages?
On the ECU side of things, do the same things apply? Do I disconnect the harness and put the tester leads of the meter in the pinout locations for the MAP and VTEC sensors I will be checking? Does the power wire go to the sensor signal and the ground wire go to the ground wire on the pinouts? Or just to a local engine ground? I put the meter selection on the OHM setting right? What reading am I looking for.... 0? Or does the meter beep or something when I have continuity? And I DO want the continuity, right? If I don't have it, what could that indicate?
Sorry, I'm just confused on how to check continuity exactly.
Fair enough. But I don't understand how the ITR ECU that was never even remotely intended to run my car runs it better than the chipped P72 that is supposed to be tuned properly for my H22A4 engine etc.... You would think it would get closer and closer to running better on the P72 as I go about fixing these various codes, right? But it seems to go more in the direction of running better on the P73 as I fix these codes...
I will check continuity tomorrow if I can figure out how to do it. Do I have to disconnect the battery? Do I keep the battery connected and have the key on, engine off? Or do I do all of this testing with the engine on and running? Do I unplug the connections at the sensors, or do I backprobe the wires like I did for the MAP sensor voltages?
On the ECU side of things, do the same things apply? Do I disconnect the harness and put the tester leads of the meter in the pinout locations for the MAP and VTEC sensors I will be checking? Does the power wire go to the sensor signal and the ground wire go to the ground wire on the pinouts? Or just to a local engine ground? I put the meter selection on the OHM setting right? What reading am I looking for.... 0? Or does the meter beep or something when I have continuity? And I DO want the continuity, right? If I don't have it, what could that indicate?
Sorry, I'm just confused on how to check continuity exactly.
Fair enough. But I don't understand how the ITR ECU that was never even remotely intended to run my car runs it better than the chipped P72 that is supposed to be tuned properly for my H22A4 engine etc.... You would think it would get closer and closer to running better on the P72 as I go about fixing these various codes, right? But it seems to go more in the direction of running better on the P73 as I fix these codes...
Concerning the continuity testing, google how to perform a continuity test.
Your meter may or may not have audible continuity testing, you may have to use the ohm setting & visually check the ohmage of each wire etc.
The car may run "better" on an ecu mapped for 240cc injectors & a 1.8L motor because:
1. You may actually have 240cc injectors & not know it.
2. If your map sensor signal to the ecu is in fact faulty & reporting a malfunction indication code 3, the ecu with the mapping for the 1.8L and 240cc injectors is supplying a different amount of fuel then the p72 is as the fuel mapping is different therefor the ecu is sending a different amount of injector pulse.
3. I have no idea what map your local "tuner" put on the p72.
Last edited by mtber; Jun 2, 2011 at 05:42 AM.
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Re: Two ECUs, 6 different CELs!
1
Turn the power OFF to the circuit of whatever it is you are testing before performing the test. This is extremely important.
2
On your multimeter you will notice a bunch of different settings. You are going to want to set your tester to read ohms. This is the symbol that looks like an "O" with feet, or more commonly known as the Greek Omega symbol. If your multitester features numerous settings under the ohms symbol, just set it to X1.
3
If you look at your tester when the probes are not touching anything, you should see a reading of infinity or OL. Touch the two probe tips together and you should see the reading change to zero. If your tester features an audio alert, it too will sound as you touch the probes together.
4
Now what you are going to want to do is touch one probe tip to one end of the resistor and the other probe tip to the other end of the resistor. If the circuit is "closed," the tester will read zero and you should hear the audio beep if it has that feature. If the circuit is "open," the tester's reading will not change.
5
Here is a clarification on what an "open" or "closed" circuit means:
Open circuit: When the circuit is not complete, meaning that no voltage is able to flow through. This can be caused by a blown fuse, resistor or a switch.
Closed circuit: When the circuit is complete, meaning that voltage is able to flow through it.
You can perform a simple continuity test on a light switch that is not wired to anything. With the switch off, probe the terminals. You should not get a reading on your tester. But, when you turn the switch on, you will notice that the tester will read zero and the beep should be heard, signaling that the circuit is closed or complete.
Turn the power OFF to the circuit of whatever it is you are testing before performing the test. This is extremely important.
2
On your multimeter you will notice a bunch of different settings. You are going to want to set your tester to read ohms. This is the symbol that looks like an "O" with feet, or more commonly known as the Greek Omega symbol. If your multitester features numerous settings under the ohms symbol, just set it to X1.
3
If you look at your tester when the probes are not touching anything, you should see a reading of infinity or OL. Touch the two probe tips together and you should see the reading change to zero. If your tester features an audio alert, it too will sound as you touch the probes together.
4
Now what you are going to want to do is touch one probe tip to one end of the resistor and the other probe tip to the other end of the resistor. If the circuit is "closed," the tester will read zero and you should hear the audio beep if it has that feature. If the circuit is "open," the tester's reading will not change.
5
Here is a clarification on what an "open" or "closed" circuit means:
Open circuit: When the circuit is not complete, meaning that no voltage is able to flow through. This can be caused by a blown fuse, resistor or a switch.
Closed circuit: When the circuit is complete, meaning that voltage is able to flow through it.
You can perform a simple continuity test on a light switch that is not wired to anything. With the switch off, probe the terminals. You should not get a reading on your tester. But, when you turn the switch on, you will notice that the tester will read zero and the beep should be heard, signaling that the circuit is closed or complete.
The car may run "better" on an ecu mapped for 240cc injectors & a 1.8L motor because:
1. You may actually have 240cc injectors & not know it.
2. If your map sensor signal to the ecu is in fact faulty & reporting a malfunction indication code 3, the ecu with the mapping for the 1.8L and 240cc injectors is supplying a different amount of fuel then the p72 is as the fuel mapping is different therefor the ecu is sending a different amount of injector pulse.
3. I have no idea what map your local "tuner" put on the p72.
1. You may actually have 240cc injectors & not know it.
2. If your map sensor signal to the ecu is in fact faulty & reporting a malfunction indication code 3, the ecu with the mapping for the 1.8L and 240cc injectors is supplying a different amount of fuel then the p72 is as the fuel mapping is different therefor the ecu is sending a different amount of injector pulse.
3. I have no idea what map your local "tuner" put on the p72.
I know I need to clear these codes. I feel like I'm chasing a ghost. One code down, 2 more pop up.
Back to troubleshooting...
Re: Two ECUs, 6 different CELs!
Thank you. It keeps referring back to a scan tool though, and I don't know what they are talking about because I don't have one anyways. I only have a meter to work with, and a paperclip lol.
This is a guide I found for continuity testing which doesn't make any sense to me in terms of how to apply it to the MAP sensor... the reason it doesn't make sense to me is because I don't know what they mean by resistor really. So I touch each end of the probes to the power and the ground of the MAP sensor wires? Do I backprobe them? Or do I unplug the connector from the MAP sensor and test them that way? Do I need to disconnect the battery??? They keep saying MAKE SURE THE POWER IS OFF. So do I need to disconnect the battery?!?! At the ECU harness, do I unplug the ECU harness and then put the probes in the pinouts??? Power and ground? Then signal wire and ground? Or signal wire and power? I only have 2 probes, but I have 3 wires to test...
...
I'm pretty sure the local tuner guy put 240cc injectors on the map. If I indeed have 240cc injectors, then wouldn't that make sense that it would run better? Assuming it's more meant for a H22 motor with 240cc injectors vs an ECU meant for a 1.8l motor with 240cc injectors?
I know I need to clear these codes. I feel like I'm chasing a ghost. One code down, 2 more pop up.
Back to troubleshooting...
This is a guide I found for continuity testing which doesn't make any sense to me in terms of how to apply it to the MAP sensor... the reason it doesn't make sense to me is because I don't know what they mean by resistor really. So I touch each end of the probes to the power and the ground of the MAP sensor wires? Do I backprobe them? Or do I unplug the connector from the MAP sensor and test them that way? Do I need to disconnect the battery??? They keep saying MAKE SURE THE POWER IS OFF. So do I need to disconnect the battery?!?! At the ECU harness, do I unplug the ECU harness and then put the probes in the pinouts??? Power and ground? Then signal wire and ground? Or signal wire and power? I only have 2 probes, but I have 3 wires to test...
...
I'm pretty sure the local tuner guy put 240cc injectors on the map. If I indeed have 240cc injectors, then wouldn't that make sense that it would run better? Assuming it's more meant for a H22 motor with 240cc injectors vs an ECU meant for a 1.8l motor with 240cc injectors?
I know I need to clear these codes. I feel like I'm chasing a ghost. One code down, 2 more pop up.
Back to troubleshooting...
If you don't get how to follow the helms manual troubleshooting guide or perform a continuity test, then perhaps you should have a shop in the area that specializes in hondas take a look at your code 3 / map sensor issue.
FYI: google yielded plenty of results when I searched for "continuity test multimeter"
http://www.youtube.com/watch?v=F0Y1XGcjlL0
Thus far, I have helped you diagnose your tps and map sensor plugs being mixed up from 1500 miles away and a brief description of the issues with your car. I would hope some one in Colorado has an idea as to what they are doing. If not, I need to open up a second location in Colorado....
Please do me a favor and choose one method of communication, email or the forum. I am getting tired of responding to both :-)
Re: Two ECUs, 6 different CELs!
In which the answers on NASIOC are still a joke, because everyone on there believes that they are an engineer that developed the car in the first place, and no one is ever wrong. NASIOC can take their website and shove it where the sun don't shine.
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Re: Two ECUs, 6 different CELs!
If you don't get how to follow the helms manual troubleshooting guide or perform a continuity test, then perhaps you should have a shop in the area that specializes in hondas take a look at your code 3 / map sensor issue.
Thus far, I have helped you diagnose your tps and map sensor plugs being mixed up from 1500 miles away and a brief description of the issues with your car. I would hope some one in Colorado has an idea as to what they are doing. If not, I need to open up a second location in Colorado....
Thus far, I have helped you diagnose your tps and map sensor plugs being mixed up from 1500 miles away and a brief description of the issues with your car. I would hope some one in Colorado has an idea as to what they are doing. If not, I need to open up a second location in Colorado....
I did finally get to performing the continuity test(s) and I will post the results in my next post to make it easier on the eyes for anyone watching this thread lol.
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Continuity test results
Well lads, I got around to doing a continuity test on the MAP sensor and the VTEC solenoid sensor as well.
I even measured continuity at every point that I could, such as in the engine bay where the engine bay wiring harness connects to the ECU harness that goes back down into through the firewall to the ECU.
From the ECU to that harness, I got: 00.3
From the harness in the engine bay to the MAP sensor I got: 00.3
The complete circuit from the pinout on the ECU for the MAP sensor all the way to the MAP sensor connector itself, I got: 00.8
Mind you, those were the sensor signal wire tests. The power and ground for the MAP sensor checked out at 01.7 (ground) and the power wire checked out at 00.6.
PS: The VTEC solenoid switch connection also gave me 00.3 readings on both wires.
So there we have it. A good continuity test, right? Or are those bad numbers? I know the closer to 0.00 the better.... but I think these are acceptable ranges for continuity?
Now we have a good wiring connection from the ECU to the sensors. The MAP sensor isn't broken. The wiring isn't. The only thing left now is the ECU right? Should I go buy a MAP sensor for an Integra and see if that helps my car? lol
I even measured continuity at every point that I could, such as in the engine bay where the engine bay wiring harness connects to the ECU harness that goes back down into through the firewall to the ECU.
From the ECU to that harness, I got: 00.3
From the harness in the engine bay to the MAP sensor I got: 00.3
The complete circuit from the pinout on the ECU for the MAP sensor all the way to the MAP sensor connector itself, I got: 00.8
Mind you, those were the sensor signal wire tests. The power and ground for the MAP sensor checked out at 01.7 (ground) and the power wire checked out at 00.6.
PS: The VTEC solenoid switch connection also gave me 00.3 readings on both wires.
So there we have it. A good continuity test, right? Or are those bad numbers? I know the closer to 0.00 the better.... but I think these are acceptable ranges for continuity?
Now we have a good wiring connection from the ECU to the sensors. The MAP sensor isn't broken. The wiring isn't. The only thing left now is the ECU right? Should I go buy a MAP sensor for an Integra and see if that helps my car? lol
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Re: Two ECUs, 6 different CELs!
Put new VTEC solenoid gasket thingys on the car today... now throwing these entirely different codes:
http://www.youtube.com/watch?v=Ah-O-L7CDBQ
That's on the P73 ECU, of course...
http://www.youtube.com/watch?v=Ah-O-L7CDBQ
That's on the P73 ECU, of course...
Re: Continuity test results
Integra/Prelude/Civic map sensors use the same part/sensor.
That video shows a code 14 (idle air control valve)
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Re: Continuity test results
Tell them a hondata isn't going to fix your malfunction indication codes if there are actual codes being thrown. Ask them to plug in an s300 system to see if you still throw the same codes on the system to rule out your p73 ecu being culprit to a random code 3 which I highly doubt...
It's like no one will touch my car for help until I get whatever ECU they want me to run. The dealer wanted me to run a stock Prelude ECU. This tuning shop wants me to run Hondata. Ridiculous. That's a good idea to tell them to plug in an S300 system and tell me what codes are popping up.
http://www.youtube.com/watch?v=nomljoWVcPE
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Re: Two ECUs, 6 different CELs!
I should add that a friend of mine suggested I try the main relay just to rule that out. Before I went in to purchase one, I wanted to verify where it was and how hard it would be to get it out. Well, needless to say I found it! But the funny thing is, there were two of them! What I mean is, someone already put a new main relay in there at some point and just left the stock one bolted up. So I plugged it back into the stock main relay just to see what would happen. The car didn't run any differently at all. So I don't know if BOTH main relays could be good or BOTH could be bad. Haha either way, I gotta chase down these CELs bad. I get like 10mpg it's pretty sad.
Let me emphasize for anyone reading... I do NOT want to go the Hondata route if it can be avoided. But if it's the only way to get a damn tuning shop with all the diagnostic equipment and knowledge to take me seriously and help me, then I will do it. I don't have a lot of money to burn, but I'm willing to spend a reasonable amount to get this damn thing fixed once and for all.
I don't know why no Honda tuning shops (professional) use anything other than Hondata? Sort of limits the competition I guess.
Let me emphasize for anyone reading... I do NOT want to go the Hondata route if it can be avoided. But if it's the only way to get a damn tuning shop with all the diagnostic equipment and knowledge to take me seriously and help me, then I will do it. I don't have a lot of money to burn, but I'm willing to spend a reasonable amount to get this damn thing fixed once and for all.
I don't know why no Honda tuning shops (professional) use anything other than Hondata? Sort of limits the competition I guess.
Re: Two ECUs, 6 different CELs!
There are plenty that do stuff on hondas other than Hondata, just not in your area. All shops will use what they are comfortable with and nothing else. In your case, you may not have much option.
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
update
Well, maybe there is hope.
I plugged the P72 in this morning just to see what would happen. Car fired up just great, and it drove pretty strong too. It felt more powerful than the P73. I mean, noticeably. CEL is still on for a MAP sensor though. I don't even know how VTEC feels or sounds like so I don't think VTEC works. But it does drive 10x better right now, which is really weird to me since all I did yesterday really was change the negative terminal on the battery (it was a little too loose for my liking) and change those VTEC solenoid gasket things. And cleaned the VTEC solenoid thing with carb cleaner and Seafoam.
So yea, I drove around today for a few short trips in town. Stopped about 3 places and each of the 3 the car fired up just fine after stopping (gas station, etc). But then one time when I had been inside a store for about 30 minutes and it was pretty hot outside, the car wouldn't start. I mean, it would start, then just die immediately. Sort of like how it was when I very first got the P72 from Phearable. The way I can get it to idle and run is give it a little gas, then the CEL comes on and it idles itself out at like 1000rpm-ish. Then I can drive it, and it drives just like before. Much more power than the P73.
I am really amazed at this point. I don't know what I did to change anything. I also don't know why the MAP sensor code is still being thrown. But here's to some kind of progress!!!! I am going to change out all the battery cables now with better wiring and add a few grounds for the hell of it.
I plugged the P72 in this morning just to see what would happen. Car fired up just great, and it drove pretty strong too. It felt more powerful than the P73. I mean, noticeably. CEL is still on for a MAP sensor though. I don't even know how VTEC feels or sounds like so I don't think VTEC works. But it does drive 10x better right now, which is really weird to me since all I did yesterday really was change the negative terminal on the battery (it was a little too loose for my liking) and change those VTEC solenoid gasket things. And cleaned the VTEC solenoid thing with carb cleaner and Seafoam.
So yea, I drove around today for a few short trips in town. Stopped about 3 places and each of the 3 the car fired up just fine after stopping (gas station, etc). But then one time when I had been inside a store for about 30 minutes and it was pretty hot outside, the car wouldn't start. I mean, it would start, then just die immediately. Sort of like how it was when I very first got the P72 from Phearable. The way I can get it to idle and run is give it a little gas, then the CEL comes on and it idles itself out at like 1000rpm-ish. Then I can drive it, and it drives just like before. Much more power than the P73.
I am really amazed at this point. I don't know what I did to change anything. I also don't know why the MAP sensor code is still being thrown. But here's to some kind of progress!!!! I am going to change out all the battery cables now with better wiring and add a few grounds for the hell of it.
Thread Starter
Honda-Tech Member
Joined: May 2011
Posts: 179
Likes: 0
From: Colorado
Re: Two ECUs, 6 different CELs!
Today I changed out the coil (Honda OEM) and the primary O2 sensor, as well as tried the new chip Phearable sent me which was very nice of him. I also tried out the spare MAP sensor he sent. Unfortunately, nothing helped this is a video I took of what happens with the Phearable basemap chip... both when I first got it and still to this day:
http://www.youtube.com/watch?v=Z6wPPFmmiww
But I know it's not Phearable's fault. There has got to be something else wrong with my car that I have not figured out yet. Of course there is the ongoing MAP sensor Code 3 CEL that I cannot figure out, but that's the only code left! I'm glad I'm narrowing down the problem...
So if it's not the ECU, the wiring, or the sensor itself, I wonder why it's throwing a Code 3 MAP sensor all the time.
I'm going to quadruple check for vacuum leaks... maybe I have a leaky TB or IM gasket? Because all the little hoses seem fine. I don't know what to do.
My next idea though is to find out where to buy the ECU plug harness pins themselves and then re-wire the MAP sensor with new wiring all the way from the sensor to the ECU directly...
this is a video I took of what happens with the Phearable basemap chip... both when I first got it and still to this day:http://www.youtube.com/watch?v=Z6wPPFmmiww
But I know it's not Phearable's fault. There has got to be something else wrong with my car that I have not figured out yet. Of course there is the ongoing MAP sensor Code 3 CEL that I cannot figure out, but that's the only code left! I'm glad I'm narrowing down the problem...
So if it's not the ECU, the wiring, or the sensor itself, I wonder why it's throwing a Code 3 MAP sensor all the time.
I'm going to quadruple check for vacuum leaks... maybe I have a leaky TB or IM gasket? Because all the little hoses seem fine. I don't know what to do.
My next idea though is to find out where to buy the ECU plug harness pins themselves and then re-wire the MAP sensor with new wiring all the way from the sensor to the ECU directly...
Thread
Thread Starter
Forum
Replies
Last Post
Geis
Acura Integra
0
Dec 17, 2015 11:20 AM
