'07 OBDII lack of communication

[xtremek]

So I'm driving the wife's '07 Explorer that has a 4.0 V-6 with a 160k on it and it starts to run pretty rough and the check engine light comes on. I limp the vehicle home and grab my Actron scanner. Turn the key on and wait. And wait. And wait. It finally tells me that it has issues linking with the vehicle. The Haynes manual doesn't have a decent wiring diagram so that I could check to see if there's a broken wire. Anyone got any help? Also the wife said she was driving the other day and the check engine light came on, the temp gage spiked and then dropped down. The light went out and the and she finished driving to where she was going. I have the same issue constantly on F-150 and I was told that it has a cracked intake manifold. I did not see the spike when the light came on for me. Thanks for any advice you can give

 

[waskly]

check the cig lighter fuse, it powers the dlc connector. one of the many 20amp fuses. if its open no scanner will talk with the vehicle.

 

[xtremek]

It's fine. the Actron powers up and the phone charges.

 

[waskly]

It's fine. the Actron powers up and the phone charges.

under the dash fuse 4 20 amp. if that fuse is good, your scanner is bad.

 

[xtremek]

The Actron was bad. I pulled the code for #3 (p0303) cylinder misfire. I pulled the plugs on the right side and they all looked decent and then ran a compression test.
#1cyl 180
#2cyl 175
#3cyl 187
The coolant is down. There is no coolant in the oil pan(the cap and dipstick are clear. I didn't see how coolant can pass through the intake. Did I miss something when I looked? If the plugs look good, I'm safe on the ignition side? And with good compression I wouldn't think I have an issue with the head gasket, valve timing, or block. I'm more concerned about the rough running. Any suggestions? Intake gasket? On the coolant thing, I'm guessing the thermostat stuck, because we haven't had any cooling issues since the one and it ran fine for at least a week after the incident.