Hello
I've got a 89 E150.........4.9L
I keep getting the code 31....KOEO.....Egr Valve Control Sensor.

The EGR Valve is new, Went to Ford, and $60.00 later got what they said was the control sensor and replaced it.

still get code 31

Anyone have any idea's

Thx John

 

Did you reset the ECM?

 

hey john, i have a 90 f-150 300-6, and i also have a code 31, i have a friend that works at ford and with the description i told him . well what the book told me was wrong they cant tell what part of the egr system is bad. They said they needed to hook it up to their scanner, mine said it was an EGR control valve fault(exc. v8), which means only for the 300 motors, this could be the valve thats bad or just the pressure sensor, dont know. I talked to a long time family mechanic last night and he said if it runs fine then leave it, he said 300's have always had egr problems, and i know i can get a valve from ford for $110, and the sensor $53, thats a lot of money to spend if you dont know for sure it will fix the problem, so i would suggest leave it till something really starts acting goofy. Hey, did you pull any other codes, i have not, did your CHECK ENGINE light come on, mine never did?

 

O by the way resetting the computer is a must since it is an electronic part, simply take the negative battery cable off, and place it on the positive side cable, for a minute or so, then the ECM will"read" the new part, otherwise if you dont it simply thinks that the old part is there. Erase the code with the code reader as well if resetting the computer doesnt work. If ya need anymore help ive me a shout.
JAMES

 

hi guys.........thx for the replies

ya I reset the puter, after I changed the egr and the sensor, but still get the code.........

 

I had a big run-in with the EGR system this summer on an 88 150 with the 4.9. I used a Haynes manual to help solve the problem but the best way to solve this problem is to understand the whole system. Vacuum is supplied to the EGR vacuum solenoid that is located on the valve cover. The computer (after using certain other engine sensor outputs) will tell the EGR vacuum solenoid to allow a certain amount of vacuum to the EGR valve. Vacuum will cause the valve to open and allow the exhaust gases back into the combustion chamber to help reduce emissions. The sensor on the EGR valve lets the computer know how "open" the valve is so it can control vacuum and so on. A couple of things can cause problems with the system. Sometimes the code you get will be the result of something else down the line malfunctioning. One thing to do first is make sure the EGR valve is functioning properly. There are relatively easy tests in the Haynes manual that will tell you how to do this with a vacuum pump. The EGR valve may need to be cleaned. It can get clogged up with carbon and not open. Make sure of course that all of the vacuum lines are OK. And finally, the Haynes manual has a nice run through of electrical tests to do on the various sensors associated with the system. I hope some of this helps. Like I said, I learned all of this this past summer and was able to fix the problem. I had a couple of EGR codes and found that the EGR valve was clogged shut and the EGR vacuum solenoid was not working properly. I fixed those and was able to pass emissions. Good luck. Post back if you have any other problems.

 

A code 31 is caused by one of three things; a bad sensor, a problem in the harness, or a bad ECM. Do this;

Disconnect the harness from the sensor, and insert a jumper wire between the brown/white wire and the brown/light green wire in the harness connector, and repeat the KOEO test. Look for a code 35. Ignore any other codes that come up. Just focus on a code 35. If it comes up, the sensor is bad. If it doesn't, it's either the wiring between the sensor and the ECM, or a bad ECM.

Post your results, and I'll help you from there.

 

I forgot to add to my post above: to clear codes all you need to do is interrupt the readout from the computer while it is giving you new codes. For instance, if you are using a code scanner that flashes out the codes, unplug it while it is in the middle of flashing out the codes. That will erase the codes

 

I tried that, it gave me some other egr codes but not a 35, so im assuming i need a new egr valve. I can get a hold of one from FORD for $109, or i might go to the bone yard and find a decent looking valve off another 6, thanks man!!

 

No, it's not your EGR valve.

Do this; disconnect the sensor, turn the key on, and measure the voltage between the brown/white wire and the gray/red wire. It should be between 4 and 6 volts (dc). Is it?

 

ok, i tried that, i had no red or gray wire..........i have a black w/green, black w/white, and orange w/yellow, i jumped from black/white, to orange/yellow, i got 5.03volts DC

 

Please don't take the negative terminal off and put it on the positive cable. One hell of a spark will be created! Just disconnect the negative side for a few minutes.

 

No spark was created, and its easier than waiting around for 30 minutes to reset the computer, besides, a well known FORD mechanic of mine said thats the way to go.

 

the other day, I read a post where someone said to simply unplug the vacuum line from the EGR valve (my engine was hesitating constantly). This worked great for me (of course you need to plug the vacuum tube). I'm wondering, however, if now the engine's going to run rich/lean and bother the converter or O2 sensor. I don't need this stuff, and am thinking about opening up the cat, but until then, my engine light is on and I'm wondering if I'm hurting anything else if it's running rich/lean.

Thanks !

 

I agree that it's a bad idea, but it won't cause a spark. Disconnecting the negative cable makes the battery no longer grounded to the vehicle, so no matter what, it can't complete the circuit.