Last week my SES light was on and off all week. After a few days the car started to run like crap and the fan was running all the time. I scanned it and got a 038 code for the MAF/MAP signal too low. When I did a live scan I was surprised to seen a line for the MAP signal. My car is a 94, I don't have a MAP sensor. I replaced the MAF sensor and all seemed well. The car ran much better, the fans were off and the live scan showed a MAP signal.

Well last night the light came back on for about a minute and scanned the same code 038. The live scann showed nothing because the light had gone out and I guess it recovered.

I'm confused, why is my ECM receiving a MAP signal if I don't have a MAP sensor? Is the MAF sensor also creating a MAP signal? I'm also a bit confused as to why the fans were running non-stop when the temp was way below 200deg.

Ideas..................

 

how is posiible that my 1994 camaro z28 have a MAP and yours not?

 

Here's where your MAP sensor is.

http://shbox.com/1/map.jpg

 

You have a map. Trust me. It's a little black box on top of your intake.

As for the low map signal. The two things that usually cause that are a big cam, or warn piston rings.

 

So this is what it feels like when you find out your an idiot. My brain was temporarly off line, but I'm OK now.

 

You also might want to check your "code" book... DTC 38 for a 94/95 is "Brake switch stuck "OFF"", at least according to Shoebox's online list, and also the list in my Chiltons. The MAP codes are DTC 33 and DTC 34.