So, I've been working on my '01 Cherokee for days now. Head gasket blew and I took care of that, yadda, yadda, yadda...

Put it back together and I'm having a problem that looks suspiciously like the MAP sensor (previously posted).

After swapping out MAP sensors with no effect, I attempted testing all vacuum hoses and electrical connections. Everything seems fine, and there's no leak at the gasket.

Then I plug my code reader in, just for S&G's.

The code reader won't even turn on. I tried it on my truck and it works fine on the truck, but as soon as I plug the code reader into the Jeep the screen goes dead. It won't even do a pocket reading with the car off.

3 Years ago the engine blew and I believe the computer got cooked a little. Did my computer finally die on me?

 

Do you have another OBDII vehicle in the driveway? (friend/family etc)? Try the code-reader on it.

 

Already did. Works fine.

 

Whoops! I just read where you answered the question before I even asked mine. . .

 

I don't know about "cooking" the computer a little...you would have noticed other prob's, chances are...first off did the reader work before the head gasket replacement ? when I get home tomorow I will check my factory wiring info and see if there is a fuse in line with the data port on my 2001 XJ...I've seen fuses blow and cause this prob on Lexus/Toyota, Ford & Chry vehicles before (all right around 2000-2005...