Where's the stinkin' computer in my 1999 XJ? Haynes manual makes no mention of its location... I want to test the signals and wiring relevant to my cruise control because I can't get it to work. Haynes schematics are pretty sketchy anyhow, they show a circuit that would have my heater fan running contantly regardless of the selector switch position, and no means of controlling the a/c compressor other than the high and low pressure switches.

 

I won't tell you where it is if all you have is a Haynes rag to go by and its the limit of your knowledge dealing with the PCM. You can do more damage fooling with the PCM than you really want if you don't have Factory Service Manual (FSM) data to go by.

Pacific Coast Manuals has FSM pdf downloads cheap.

 

Isn't is in the LF corner? Right by the air filter housing? If you don't know what the PCM looks like, probably shouldn't mess with it.

 

Well I could use your help, but at 54 yrs old with about 35 of those as an electronics tech, I can do without the judgement, so how about keeping that to yourself? All I want to do is confirm that the brake light switch isn't locking out the cruise control function and that the wiring to the modulator is good. If you're not interested in being helpful, that's fine. This is a 15 year old Jeep, not the Space Shuttle...

 

Sorry, but this forum is not a virtual FSM. I am interested in helping others but sometimes it gets out of control going back and forth with posts upon posts, digging up wiring diagrams and posting them, on and on, ad nauseam.

Maybe someone will jump in and give you step by step guidance with your issue, but you are better off getting a FSM to use as guidance.

As stated, Pacific Coast Manuals has pdf downloadable FSM's for $7.99.

Edit: I'm 70 years old with 43 years as an aircraft mechanic, and more than that dicking with automobiles. BFD.

 

I'm sorry but this made me laugh!! All those years as an electronic tech and you have no idea what the PCM looks like...

 

I'd be a little hesitant to flash your "credentials" around here when asking a silly question like that. Did you even look for it??

 

i lol'd my gf knows where it is without me telling her

 

I have forgotten more than most of you know...... but damn I wish I could remember a little of what it is I have forgotten in 66 years

Because now I have CRS syndrome and it affects yesterday

For those who do not know what CRS is, wait a few years and it will come to you.

 

Do you know for sure that the problem with your cruise control is electrical? You may have a vacuum leak. The PCM is mounted on the driver's side fender w/three harnesses.

 

I know many of you have a lot of knowledge about Jeeps and have helped me out specifically but wouldn't this been more helpful if someone with a '99 just told the man where the hell the damn PCM is located instead of making condescending remarks? Think of the first day you got your Jeep and someone walked over to you and asked you to point out the PCM....Come on guys...

 

All you have to do is open the hood at it's right in front of you. He's getting so much grief because of his comment of "54 yrs old with about 35 of those as an electronics tech" and he can't spot it.

 

I used to know what CRS means.