This post is a follow up to one last week about an EGR code 32 problem on my nephews 88 4.9 F250 4X2.

Egr valve works, almost no vacuum is required to pull the valve open. The intake port is clean. The line going to the passenger side is clean for 24 inches(that is the length of the pipe cleaner I had.)

Throttle body is clean.

Egr controller (or solenoid) is new. Yes the old one was bad.

All vacuum lines are new. I am still getting code 32, and when I clear the codes, it re-appears within 10 seconds.

Now what should I look for??

Does the truck have to be hot to get a vacuum signal from the computer??

If so, when should I get voltage to the vacuum solenoids??

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

I have shop manuals. But just realized I do not have volume “H”, engine/emissions diagnosis manual.

Any help is appreciated. I need to get this thing inspected.

 

what is code 32? engine doesnt have to be warm but its nice.

 

code 32 says the sensor on the egr valve shows voltage below the closed (valve closed) limit. The EVP sensor should have a closed Resistance (unplugged from the harness) of 5000 ohms and 100 ohms when the ERG valve is wide open. There are several checks in the Haynes book that are relatively easy. You need a volt-ohm meter and a vacuum source (hand held vac pump). There are several checks, but you need the tools and the book. You may have a faulty ground in the sensor circuit. I could tell you what the book says but , it would be a waste of time if you don't have a volt/ohm meter. It sounds like you have a EVP sensor circuit problem of some sort--bad connection-corroded contact-low sensor voltage-broken wire -high resistance contact/connection.

32
(KOER) EGR not responding properly during test.
32
(KOEO, KOER, MEM) EVR,EVP signal is/was low.
32
(KOER, MEM) PFE shows low pressure, EGR not seating or memory, not seating intermittently

 

i have come to the conclusion that it is most likely a bad computer, due to a few things.
#1, i get no power or ground signal to the egr vacuum control solenoid, or the 2 air vacuum control solenoids.
#2 i have 6 volt, and ground to the egr sensor, but no apparent signal.
#3 all grounds are now clean, and i am able to clear codes now, and do koeo and koer scans.
i need to find a pinout box to make sure, but everything is pointing to a bad computer.

 

Why would that lead you to a bad computer? The computer doesn't power up the solenoids. That is done by the EEC relay. If that was the issue you would have power in very few places in the engine management system. The EEC relay powers pretty much everything on the engine that needs 12V to work. If you are getting no signal out of the EGR pos. sensor I would consider that to be a problem. IIRC, it should output aroung .35V KOEO. If you've got reference voltage and ground, but no output the sensor is bad. It seems like I remember something a few years ago about some of the sensor plungers were too short and that screwed up the closed voltage.

 

OK, the 6 volts to the EGR sensor is correct ( book says 4-6) there is no signal as such . The EGR sensor is a variable resistor, with the resistance being varied by the movement of the EGR valve, the computer looks at the voltage drop across the resistor to tell the position of the valve. The EVR valve controls the vac to the EGR valve and should have +10 volts on one of the pins with the key on. That power--10 volts min.---comes from the EEC RELAY (it also feeds the computer/PCM on pins 37&57 RED wires -PCM connector) ( the EVR ground is pin 33) and not the computer.
TIP -------------> REPLACE THE EEC RELAY< --------------
cheap from Ford $20, it supplies power to the computer and some other components. It is a small single metal cased relay on the drivers side inner fender apron. It can wreak havoc with trouble shooting and cause the engine to die at ANY time or not start. It took me a week of solid trouble shooting to find out why my truck died at the most inopportune times. The relay had water in it from a dealer steam cleaning before I bought the truck. I would change the EEC relay before I changed the computer, they are pretty reliable.


stractor

 

Does the truck have a problem with stalling, or just a CEL from a code 32? If it was the EEC relay I think he would have much more significant symptoms than a CEL.

 

the truck runs fine. no burps, hiccups, or backfires. it purrs, never stalls, always starts rite up, and gets 11-14 mpg.
the only reason i am even messing with it is the fact it is due for inspection, and it is an instant failure if the cel is on, whether it passes all the tests or not.
and removing the bulb is not an option, they check for codes, and "road-ability" which is basically to see that the vehicle has been started and shut off 20 or 40 times since the codes were cleared. when they started doing the new inspection, people were clearing the codes in line before they got to the door hoping the light would stay out long enough to get through the tests.

the egr valve works when vacuum is manually introduced to it, so that is good, and the egr position sensor is new, and i tested it before installing it, and it tests good.

 

Unless I am mistaken ( It happens a lot) your 88 like my 90 doesn't store information like that They are OBD1 systems and the newer ones are the OBD2 systems are the ones they look at. I am also in NJ and the last time I had the truck inspected , this year, they didn't do any diagnostic tests (the connector is under the hood) only the treadmill test for emissions.

stractor

Found this

Two types of test are now used in New Jersey. For vehicles manufactured before 1996, a treadmill is used to monitor emissions during acceleration. For vehicles manufactured in 1996 or later, New Jersey uses the On-board Diagnostics, or OBD, test

 

ok, but it still will not pass with the cel on.