Dead ODBII port on 2001 Sport

[CHH777]

Well, my friend's CEL is on so I old her she needed to have it scanned. Local auto parts store told her they couldn't do it and she'd have to go to the dealer. I took a shot at it with a cheapo scanner and discovered the ODBII port is dead. Any ideas on where to start without going straight to the dealer?

 

[aldive]

The '91 is OBD I not OBD II.

 

[410Fortune]

this is a 91 Explorer sport?
Then it's OBD-I

Are you using the correct scanner?

I have run into a problem like this before.
I pulled the wiring to the diagnostics port apart about 8" worth and foudn the problem.

You can do a self test with a paper clip that will likely work without using a scanner.
You see the scanner also gets its power from a + and - signal inside the diag port.
The paper clip method does not require this.

Do a search for that.

1991 or 2001?

 

[CHH777]

Oops, Make that 2001 Sport.

Thanks...

 

[410Fortune]

what do you mean dead?
What scanner are you using?

 

[CHH777]

Scanner=CReader. Display does not light up. I checked it on 2 other vehicles (w/codes) and it worked fine.

 

[410Fortune]

was the key turned?

Some scanners use batteries and can pull codes even if there is no power to the OBD-II port. (Snap on)

The scanner is typically powered by a + wire from the PCM.
You can check the pinout and check the wiring to the PCM harness one by one
pain in the ass.
I believe only one wire goes tot eh GEM module all the rest go directly to the PCM. So if it's not a bad wire it might be a bad PCM itself.

Is the truck running allright?

 

[CHH777]

Engine was running during attempted scan (per instuction manual).

Did not get around to checking pinouts as it was dark outside.

Truck seems to run fine.

 

[Jefe]

Does the 12v port work on the dash? For whatever reason Ford put the OBD port power with the cig lighter circuit on the fuse panel.

http://www.explorerforum.com/forums/showthread.php?t=116392

 

[CHH777]

No, the cigarette lighter is dead (along with the electric side mirrors & wiper sprayer). Same circuit?

 

[410Fortune]

check fuses

 

[CHH777]

Anyone know what fuse for cig. lighter? She lost her owner's manual years ago...

 

[ExplorerDMB]

I ran into this same problem when trying to hook up my NGS. I forget which one it was, but just pull fuses and look at them to see if their broken up. Good luck.

-Drew

 

[Lloyd10977]

Anyone know what fuse for cig. lighter? She lost her owner's manual years ago...

Check this page for the user manual:
http://www.motorcraftservice.com/vdirs/ownerlit/default_retail.asp?year=2005&vehCode=exp

 

[ExplorerDMB]

For my Explorer it was fuse #17. Hope this helps

-Drew

 

[CHH777]

Thanks all. Fuse 17 was blown. This site and its users rock!

Happy New Year to all...

 

[MONMIX]

since replacing the fuse
do you still have the CEL ?
Does the scan tool work now ?

 

[CHH777]

Scan tools works now. CEL still on. Codes 174 & 176 I think...

 

[CHH777]

Correction: Codes 171 & 174.

 

[CHH777]

Vacuum return line had collapsed (at elbow). Replaced with a piece of heater hose; reset codes and it runs fine again...