Cant Read ECM Codes

[Partycove2]

Hi All, New member to this forum. Seems like allot of knowledgeable people here. SO here is my hello!

My question, 2004 Explorer Eddie Bauer with 4.6 V8.
Recently started idleing lower than normal (around 450) only when truck is warm and in gear. When coming to a stop it drops to about 450 with some shaking from the lower than normal idle, then about 5 seconds later comes up to 500 and shaking goes away. Truck runs fine other than that.
Only once did the check engine light come on about 2 weeks ago and I reset it and it has not come on since, but the idle issue is still there

Anyway, I tried to read the codes this weekend and all I get is an ERR on the code reader(model 3100) Tried it with key OFF, key ACC, and Key ON (not started). The reader does turn on when it's connected so I know there is power to the OBD connector

Any ideas at to what could cause these problems?
Also, anyone know where the ECM/PCM is located on this truck and where I can find a wire PIN out from the OBDII connector to the ECM

 

[BrooklynBay]

Welcome to this forum! What are the code numbers?

 

[Partycove2]

I cant get the codes, that is one of my problems. The reader is not communicating for some reason

 

[BobWiersema]

Try it with the engine running. If you still get nothing, try the reader on another car to make sure its ok.

 

[jakedrew]

my actron reader didnt work on my 04. but that scanner was only obd2

Isnt 04 THE "c.a.n" stuff?

I bought a craftsman scanner and it worked.

 

[BobWiersema]

If its the Equus 3100 it should work fine.

More Info is required for us to help.