[T&J]

Where can I rent a breakout box? I have found them online, but they are $400-$800, but I do not want to pay that.

Can I rent one somewhere?

I am trying to preform the test in the documents below.
http://ylobronc.users.superford.org/documents/egr/

Thanks

 

[SigEpBlue]

You know that almost always, those pin numbers are the same numbers as the PCM connector pinout, right? You can backprobe those pins right at the PCM, too. Ya really don't need the BoB for EVR/EVP testing.

I know, not really "an answer to your question," but it is a poignant observation.

 

[T&J]

Sig,
check out this thread...maybe you can help
http://www.fullsizebronco.com/forum/showthread.php?t=118241&highlight=EVP

Honestly I wouldn't know what to look for when back probing the PCM. This is kind-of my last idea on code 31.

 

[SigEpBlue]

Check your linkage. I got a 404 error.

 

[LYVFD8142]

T&J I just wrote up a way to check and fix the Code 31, search. It's a pretty easy fix more than likely.

Remove the EVP (3 screws). Then spray a little lube in on the diaphragm edge and then get a Phillips screw driver and push up the diaphragm from one of the small holes at the bottom of the EGR valve, it doesn't take a lot of pressure to get it to move. Then replace the EVP and the 3 screws and retest the system. That should fix the system. If not you will need to test the EVP sensor.

Let me know if that fixes it if not I can walk you through the EVP test with a multimeter.

 

[T&J]

Check your linkage. I got a 404 error.

:thumbup

Fixed.

Thnx

 

[T&J]

T&J I just wrote up a way to check and fix the Code 31, search. It's a pretty easy fix more than likely.

Remove the EVP (3 screws). Then spray a little lube in on the diaphragm edge and then get a Phillips screw driver and push up the diaphragm from one of the small holes at the bottom of the EGR valve, it doesn't take a lot of pressure to get it to move. Then replace the EVP and the 3 screws and retest the system. That should fix the system. If not you will need to test the EVP sensor.

Let me know if that fixes it if not I can walk you through the EVP test with a multimeter.

LYVFD,
I have have replace/tested/fixed everything I could possibly do. Today i went through and retested everything. Check out my original thread above. I ended up going through 3 different EVP sensors before getting one with the correct ohm reading.

I also just replaced the wiring harness with a nice one I found at the JY as well as an EEC swap.... no codes expect 31....STILL

 

[SigEpBlue]

T&J I just wrote up a way to check and fix the Code 31, search. It's a pretty easy fix more than likely.

Remove the EVP (3 screws). Then spray a little lube in on the diaphragm edge and then get a Phillips screw driver and push up the diaphragm from one of the small holes at the bottom of the EGR valve, it doesn't take a lot of pressure to get it to move. Then replace the EVP and the 3 screws and retest the system. That should fix the system. If not you will need to test the EVP sensor.

Let me know if that fixes it if not I can walk you through the EVP test with a multimeter.

Did you even read his other thread?



Anyhow, are you still having that problem getting VREF to the EVP connector? If so, you've got to start there. Without a reference voltage going to the sensor, no voltage will ever be returned to the PCM. There has to be a fault between that EVP socket and its connection in the harness; it shares VREF with most other sensors (TP, MAP, etc.). I would also give up testing resistances with sensors. The PCM only 'cares' about voltage values returned.

 

[Fireguy50]

you can buy one on eBay for ~ $100

 

[T&J]

KOEO
VREF and SIG return I get 5.0v
VREF and EVP Signal I get 3.7v


I can't find any test for the just EVP Signal wire (expect with a BoB).

The funny thing is that I have tried 2 different wiring harness' and 2 different EEC-IV....and I still only get KOEO/KOER 31.

 

[LYVFD8142]

I read the top thread that showed the pictures.

Ah, I see he fixed the original thread link, sorry guys...

 

[T&J]

you can buy one on eBay for ~ $100

Thnx Ryan.

Any instructions on how to do those test without a breakout box?

 

[LYVFD8142]

Have you used the multimeter to test the continuity on the harness and checked the resistance of the harness? Have you backprobed the pin for the EVP on the EEC? You can get a paperclip to push in the connector (for the EVP pin) and then use the multimeter to read the voltage.

 

[T&J]

LVYFD,
no I haven't. I am not sure how to do that exactly... In my original thread I asked for help on how to do a continuity test and got ZERO replies. I search online and found nothing as-well.

So if I test the resistance between the EVP Signal wire (at the vehicle harness connector) and at pin 27 (EVP Pin)...what should I get?

I am just finding it hard to believe that 2 different wiring harness' and 2 different EEC's are getting the exact same code....

Please forgive me, but this is the first EFI car that I have worked on and I am still learning.

Thnx

 

[LYVFD8142]

I will check mine tomorrow and see what ohm reading I'm getting.

A continuity test is used to check if there is a physical connection between point A and point B. Most multimeters will have a buzzer setting so you can hear it or you can set the ohm setting to the lowest setting and touch the 2 leads together and you should get 0 ohms, then you test the harness by putting the ground lead on one end of the harness and the read lead on the other end of the harness. If it's the correct wire then you will hear it beep and/or you will see the ohms resistance of the wire. If you get no sound or no number then you are either on the wrong wires or there is a break in the harness wire.

While the harness is connected to the EEC you can continuity test from the EVP side (disconnect from EVP) and check each pin with the red lead while the black lead is connect to a good ground (like the battery). Make note on any pins that beep and post them. You should only get a beep on the Sig Rtn IIRC.

Generally if you get 2 of the same thing and you get the same results then you look at the common items and then rule them out. So you've stated the EGR valve and the EVP sensor checked out good (in working range for voltage and resistance) and you have tested with 2 different harnesses then the only item left is the EEC computer itself (I can't remember if you stated you replaced that or not, i'll go back and reread the original thread again).

All my reference materials are in my truck so I'm doing this off the top of my head. And my poor brain cooked a little today while standing in the sun all day.

 

[SLOFordtech]

a breakout box is just like the pcm connector harness side but eaiser to test at, what ever break out box pin it says to test at, just test at the pcm connector harness side pin, should get you the same results, plus your connector should be real easy to get to especially if you pull the fender well if you only got 3.7 v vref somthing is taking up some extra voltage that is in series with the evr signal wire, test ohms with a multi meter from the evr sig wire at the pcm connector harness side to the signel wire at the evr sensor connector harness side, do this with both connectors un plugged(pcm and evr), check spec from the pin point test your doing and compare. if that makes sense. hope so im not good at explaining hope it helps, i didnt read every reply so if someone already explained this sorry....

 

[T&J]

Thnx for the help LYVFD!:thumbup

So I checked resistance between pin 27 and the EVP signal wire....and put the DVOM on the lowest ohm setting (200) and got 00.5

I only preformed the test on the wiring harness that is not in the vehicle and I will check the wiring in the vehicle tomorrow.

If I get the same resistance on both harness' and it coinsides with the reading you get from your harness....what do I do next?

Thnx

 

[LYVFD8142]

You can plug in the harness to the EVP and then on the EEC side do the resistance check that the manuals says and see if your still getting the correct readings. By doing that then you have pretty much ruled out the harness and the EVP sensor (you may need to remove the sensor to test tho).

 

[T&J]

a breakout box is just like the pcm connector harness side but eaiser to test at, what ever break out box pin it says to test at, just test at the pcm connector harness side pin, should get you the same results, plus your connector should be real easy to get to especially if you pull the fender well if you only got 3.7 v vref somthing is taking up some extra voltage that is in series with the evr signal wire, test ohms with a multi meter from the evr sig wire at the pcm connector harness side to the signel wire at the evr sensor connector harness side, do this with both connectors un plugged(pcm and evr), check spec from the pin point test your doing and compare. if that makes sense. hope so im not good at explaining hope it helps, i didnt read every reply so if someone already explained this sorry....

SLO,
I want to make sure I am understanding this right
VREF (pin 26)=Volt Reference and that is power
Sig RTN (pin 46)=Ground
EVP (pin 27)= EVP sensor signal to PCM

When I did the EVP circuit check (VREF and Sig RTN) at the sensor connector in the KOEO I recieved 5.0 volts. Haynes say that voltage should be between 4 and 6 volts, so I am good there. That tells me that I am recieving power to the EVP sensor and the ground is good.

Then I did the same circuit test between VREF and EVP and got 3.7 volts. I did not see that test anywhere, I just did that to see what would come up.

Then I did test DN7 "Check EVP Signalf or short to power"
-key off, EVP disconnected from harness
-I turned my DVOM to 200K
-Measured resistance between test pin 27 with 26 and 57.

I got nothing.... what am I doing wrong? DN7 asked if both are greater than10,000 ohms.

thanks

 

[T&J]

You can plug in the harness to the EVP and then on the EEC side do the resistance check that the manuals says and see if your still getting the correct readings. By doing that then you have pretty much ruled out the harness and the EVP sensor (you may need to remove the sensor to test tho).

Good idea...

I should back probe test pin 27 and test pin 46 on the EEC...then turn the key to the on posistion and see if I get between 4 and 6 volts.