Diagnostic plug not reading

Green Turd · January 31, 2006

Hey guys, I am a 97 Ranger owner myself. My dad has a 2002 Explorer and his CEL has ben on for a while. I took it to Auto Zone for them to pull the codes for me, and they could not get it to scan. It is like there is no power coming through the plug...almost like a wire was loose. I have checked the connection and everything seems to be in order. 7 wires leading to 7 pins. Has anyone ever heard of this happening before. I can't read his codes if the scanner cannot connect to the ECU and he needs an emmissions test which he WILL fail automatically if the CEL is on. Any ideas? I also went to an Advance Auto Parts to make sure that it wasn't the guys tester. They told me I would have to go to the dealer but I hate doing that and would love to avoid it if possible.

410Fortune · January 31, 2006

Searchity.

Check the fuse for the cig lighter

this was just covered on this forum.

Also I recently learned that CO emissions rules have changed in the last couple of years, a CEL does no longer mean automatic failure, because the CEL will illuminate for transmission related issues as well as emissions sensor issues. Might want to check the GA rules.

Green Turd · January 31, 2006

My apologies I did a search but it was for "diagnostic box" and "diagnostic plug" and got no helpful results. Thanks for the input. I will try a little harder before posting next time. I know how frustrating answering the same thing over and over can be.

410Fortune · January 31, 2006

no no its not frustrating, I just always try to point people in the right direction is all.
If you are having a problem 9 times out of 10 somebody else has had the same problem and it has been discussed here.

Searching can be a PITA, but trying different words, etc will usually get you there.
It's an art form

Green Turd · January 31, 2006

Yeah, I am a member on another forum...mx-3.com. And searching is sometimes really hard to narrow down to usefull info. I just assumed that as strange as this problem seemed to be that it was a new one since I didn't find it doing the basic searches. Thanks again for your help. Just a simple fuse huh? That is crazy. I wonder what the dealership would have come up with. Aww you need a completly new wiring harness or some bull stuff like that.

410Fortune · January 31, 2006

well its new to me too but I jsut read about it last week I believe.
The + wire for the OBD-II port is inthe same circuit as your console mounted cig lighter I believe, I would check that fuse.

Also an OBD-II port that is not getting powered by the truck can still have the codes pulled using a scanner with this ability. The Snap ON Scanner my trans guy has has batteries and is able to power up the PCM and pull the codes itself without the diag port getting 12 V +

Green Turd · January 31, 2006

Yep...that makes sense to me. The tester wouldn't even light up because it was not getting power. I am checking it now that I am leaving work and will post up my results.

Green Turd · January 31, 2006

That did the trick. I got the codes pulled and It came back with PO401. I have been sitting here reading and I believe that it is probably the DPFE Sensor. It sounds like that little f-er has gone out on everyone. My Dad has a 2002 should this have gone out so fast? He only has 45,000 miles on it. He has probably ran the damn thing with the CEL on for 5k though. Arg...i finally just traded keys with him and am taking care of it myself. Lazy Old Geezer! :fire:

410Fortune · January 31, 2006

check the vacuum lines on the sensor, check the EGR tube itself for a hole, and check the diagphram in the EGR valve itself before you run out a buy one.

Green Turd · February 1, 2006

I will have to disconnect the battery to clear the code right? About a month ago I just disconnected the battery to clear the codes and see what happened. It stayed off for a week and a half...probably 250 miles. While the light was out my dad tried to get his emmissions tested and they told him that he has to drive 250 miles or so after disconnecting a battery before they can do an emmissions test. Well hell, as soon as he hit the 250 miles the light came back on! What's up with that?

ExplorerDMB · February 1, 2006

Your getting into "Trips" and "Drive Cycles" now. Monitoring Test and all that good stuff.

Check out here: http://www.explorerforum.com/forums/showthread.php?t=148433

Scan through there and you'll find a great load of information. Also, if you have a scan tool - just erase the code with that. But yeah, the battery will clear it, but it has to go through all of the monitors until you'll be able to emission test it so the people can see that all the monitors and sensors are working correctly.

-Drew

by the way, moved this to EEC-V section since it deals with that.

Green Turd · February 1, 2006

Thanks for that awesome info. The guy at Advance Auto told me that I would have to complete the drive cycles and said basically what you are saying. He hinted that there was a procedure for "building the memory back up in the ECU". The write up that you sent me the link to is exactly what I needed. That all makes perfect sense to me. I had they guy at Advance clear the code with their scanner but he told me that I would still have to perform the drive cycles. He told me to call a local Ford dealership to ask them what the procedure was for reseting the monitors. When I called he said that there isn't one, you just have to drive 250-500 miles. Either he just didn't want to explain how to perform a drive cycle over the phone or he didn't know that there was such a process. Either way...it shows why I hate the dealership.

410Fortune · February 1, 2006

Key on, drive, key off
Key on, drive, key off

Those are drive cylces.
You see fromt he factory the computer has base line settings and acceptable paramaters for many of the sensors.
As you drive it learns what your sensors are telling it and picks fuel/air/spark/shift curves based on your elevation, fuel, and driving style.
It stores those in memory and then once the "break in " period is complete it has the information it needs to start functioning normally day to day.

Thats in laimans terms for you and me.
It is not a certain # of miles, but more time driven and amounts of time the vehicle is driven. I am guessing 250-300 miles is about the average it takes most people to reach that point.

Green Turd · February 13, 2006

Thanks for all your help guys. I replaced my dads DPFE Sensor and he drove enough miles to rebuild the memory in the ECU. Saturday he took it in for the emissions inspection and passed with flying colors. Thanks Again. Saved him a big bill at the dealership.

ExplorerDMB · February 13, 2006

tell him to spend 20 for you to become Elite. We help you - you help us. That's the way it should work.

-Drew

frankwr · July 18, 2009

You might want to consider buying your own OBD tester. You can buy a basic unit for under $40 when they're on sale. I use mine for all my family members car too so they can check before they get ripped off by unscrupulous "repair experts" !! It's a great investment and beats driving off to an Autozone etc.

Diagnostic plug not reading

Green Turd

New Member

410Fortune

Truck Season!!

Green Turd

New Member

410Fortune

Truck Season!!

Green Turd

New Member

410Fortune

Truck Season!!

Green Turd

New Member

Green Turd

New Member

410Fortune

Truck Season!!

Green Turd

New Member

ExplorerDMB

Moderator/Technician

Green Turd

New Member

410Fortune

Truck Season!!

Green Turd

New Member

ExplorerDMB

Moderator/Technician

frankwr

New Member

Explorer Features

Explorer Features

Similar threads

Featured Content