I'm new to these code readers. Just got one from advice on here. Ymeski I believe. Thanks for the link. Great board by the way.

Here's my situation. My Nox levels are very close to the failure level, just 2ppm to the good. It just passed last month so I have a year to get it right.

Egr valve works with outside vacuum applied. Doesn't seem to get vacuum to it though. I replaced the solenoid back up the line with a new one. Same result only now the Check Engine light comes on after a while of driving.

I'm getting a 558 code. It's defined as "EGR valve regulator solenoid circuit fault". I kind'a figured that one on my own. I imagine that refers to the electrical circuit. Now when I turn on the code reader I can place my hand on the two relays behind the EGR regulator solenoid. When the self test is run they seem to both click. Don't know where to go from here. Don't have a shop manual.

Truck is a 5.0 liter with a few miles, 287,000. Uses oil but otherwise runs fine. No missing.

Any ideas appreciated.

 

Code 558-EGR vacuum regulator solenoid did not respond. The self test looks for battery voltage during the solenoid off command and voltage under 1 volt during the solenoid on command issued during the self test. Normal solenoid resistance is 30-70 Ω. PCM pin #33, wire color is brown/pink. You may hav a poor ground too.

 

http://fordfuelinjection.com/?p=43

most sensor questions can be answered from that page.

 

Thanks rtg143. I'll check the solenoid resistance. I did just replace it. How do I locate the PCM and pin #33?

 

Thanks for that link Talmbla. That will give me some direction come morning. Now I know where pin #33 is. It's my understanding the computer grounds that pin to connect the vacuum lines to the EGR valve. Where do I find the computer? Maybe there's a poor connection.

 

It's behind the drivers side kick panel. The harness bolts to it from the firewall side.

 

Update. Back from the grave, so to speak.

I was able to start looking for problems this morning. Did the recommended grounding of pin 33 at the vacuum regulator solenoid with everything connected and engine running. http://fordfuelinjection.com/?p=43 Big spark engine dies. Won't start. OMG. What have I fried? Surely the brain.

Thankfully not. After 2-3 minutes of panic I went looking at fuses. Found a big one (20 amp) fried in the power distribution box. It runs the fuel pump relay coil and Power train control system. Replaced it and now we're running again. Everything seems fine.

I definitely have a short. Pin #33 has 14 volts going to it, instead of being a ground. Usually do my own simple repairs not AC though. About 3 months ago had to have my expansion valve/evaporator coil replaced. Other wise not much else. Don't have any other problems with the truck, except the air bag light does flicker some. Both fuel pumps work.

One other thing, I did notice one of two nuts holding transmission to the cross member was missing. I replaced it last week. Doing that removed a creaking sound when I would take off. I suspected a loose body part, but apparently it was the drive train moving around. I'm wondering if maybe a wire bundle could have gotten the rub because of this movement. Any thoughts.

 

the movement of the trans rubbing/pinching wires is POSSIBLE, however UNLIKELY. thats very limited movement. i drove my truck from alaska to illinois with neither nut on the trans cross member. makes me feel good when i spend 1000 dollars to fix a trans leak that sprang back up 600 miles down the road, and the nuts were missing...and i think they fudged my trans wire harness plug on the reinstall...lol

 

Not resolved yet, but made a positive move this afternoon. Turns out the vacuum regulator solenoid (EVR) I just purchased was also defective. Zero ohms resistance. That's why it blew the fuse when I grounded pin33 for the test. Not out of the woods yet though.

There is still an apparent electrical break between the computer and the EVR solenoid. Otherwise the fuse should have blown again driving around with the defective EVR. It's my understanding the computer grounds pin33 to engage the EVR and open the EGR valve. I drive 25 miles to work everyday highway speed. Nothing happened today. Thankfully I guess.

Does anyone know if there is anything else associated with pin33? Or is it just the EVR solenoid? Thanks.

 

Just the solenoid.