Mudtallica

Hey all.. After searching for answers on here, I'm not finding anything that matches my problem so I had to write this up to see if there's any answers out there.. Got a '98 Laredo, 4.0, Auto.. My wife started it to warm up before they left for school & when they walked out 5 min's later, it had died.. It wouldn't start back up.. When I got home, turned ignition switch on, all light in dash come on & go off like they should.. Noticed fuel gauge didn't move, thought, "Well, there's the problem.." .. Turns out, no, plenty of gas.. I'm thinkin' the gas hand would move to show level in tank with the key switch on.. I could be wrong.. Anyway, check for voltage going to FP.. No power.. Checked the voltage at the CSP sensor plug.. Good.. Pulled a plug... No fire.. Checked the wiring going to ign coil.. No pwr.. I should also note that the CEL was NOT on.. Plugged up my scanner to check some things but it won't "Link Up" with the computer.. Does this sound like the PCM gone bad??

Bob98Classic

Your situation sounds similar to mine on my 97 I bought a couple of months ago. No power to coil, scanner not linking up, etc. I work alot of
hours everyday, hard to find time to work on the XJ. Anyway, good luck.

Pelican

Do Grand's have a Laredo Model, ie. is this a '98 XJ?

I assume you are referring to voltage at the CPS plug but presence of voltage does not necessarily mean that the CPS is good. AFAIK a failed CPS does not necessarily cause a CEL but I may be wrong about that.

Don't know about the failed scanner/PCM link-up but I wouldn't think it likely that a PCM would just up and fail while the Jeep is sitting idling for a few minutes.

I'm really just trying to get something started here because I have no experience with scanners and late model XJs. Any other symptoms recently?

Mudtallica

Sorry for not replyin' back too quickly.. Been busy.. Got it runnin' this past Sunday.. Turns out it was the CPS.. After searchin' a bit, found that if you check the vltage on the TPS, then unplug CPS & voltage changes, the CPS is bad.. Would've never thought this 4 wire contraption can keep voltage from going to FP, ign coil, & even the guages.. Swapped it out & it fired right up.. & Pelican, I believe this is a ZJ...

Bob98Classic

Glad you have your Jeep running now.

I will change parts from my 98 to the non running 97 to see what

my problems are.....