: Where does the MAP sensor connect to?



Cadillac Giovanni
07-17-09, 04:37 PM
short while back, I replaced the fuel filter in my Brougham. Ever since, I've been getting a check engine light, which occurs whenever the engine first ramps down after having warmed up. If the engine doesn't warm up, the light won't come on, and it won't come on if I keep the RPMs up, like driving on a highway, but the second I slow down, it comes on.

Anyway, I used the neat pin-jumping trick to pull a code 34, "MAP sensor circuit error". I went to check the sensor, everything seemed okay, visually, until I traced the vacuum hose over to the engine and found it wasn't actually connected to anything.

I figure I must have unplugged it accidentally while I had the air cleaner off to change my filter, but I'll be damned if I can find where it's supposed to go back! There's a myriad of lines and hoses in that area, so I wouldn't be surprised if it was staring me right in the face.

sven914
07-18-09, 12:42 AM
The way it is on mine, is the vacuum hose goes into the wiring harness and comes out in front of the carburetor, to the right a little. There should be a 4 way connector with 2 of the connectors on the top side, and one on each side (right and left). I'm pretty sure it is routed to the top connector on the left (driver's side), but I'm not positive.

I do not have a picture of where the MAP is routed to, but the one of the hoses from the connector, the MAP is routed to go to the black round object in the upper left hand corner of the picture (CANP valve I believe). That very thin line, that goes into a thicker rubber hose, in the upper center of the photo is the hose for the MAP.

http://sn116w.snt116.mail.live.com/att/GetAttachment.aspx?tnail=3&messageId=0f6f4e39-37a5-4a91-917a-bbfab4854e3b&Aux=44|0|8CAFBAD41278900|

I'm sorry and don't mean to :hijacked: you, but since I dug up this picture; does any one know where that hose, with the bolt in the end, lives?

Cadillac Giovanni
07-18-09, 01:24 AM
I can't see the picture for some reason, but I have a hose with a bolt in the end as well, and it goes to the EGR valve over the left valve cover.. It's blocked because the engine runs rather poorly at idle when it is connected. That could be what it is.

sven914
07-18-09, 03:57 AM
This better.

http://www.cadillacforums.com/forums/picture.php?albumid=375&pictureid=4411

The other one worked in my Firefox browser, but not Explorer. I found it in an e-mail I sent 2 years ago. This one I dredged out of darkest realms of my computer; from a folder marked TEMP, where it sat next to a program I downloaded in 1999, and forgot about.

sven914
07-18-09, 06:42 PM
Here is a better picture I took today.

http://www.cadillacforums.com/forums/picture.php?albumid=375&pictureid=4434

sven914
07-21-09, 05:10 PM
I have a hose with a bolt in the end as well, and it goes to the EGR valve over the left valve cover.. It's blocked because the engine runs rather poorly at idle when it is connected.

The hose for the EGR runs to a vacuum control box on the driver's side of the engine. Looking at it there should be 6 vacuum connection points; four at bottom of the box, and two close together on the top. The Hose is supposed to be connected to the forth connection (going towards the fire wall), which is the last one on the top of the control box.

If your car runs poorly with the EGR connected properly, then you may need a new EGR valve.

Cadillac Giovanni
07-21-09, 09:23 PM
Yeah, now that I can see the the picture, that's definitely not the EGR hose. I can't say what exactly that goes to...

Thanks for the pictures, it helped a lot!