Please move if not correct section!



Hello guys, I've recently got a Jeep Grand Cherokee 1998, 5.9 v8. I know, not a dodge, but I've been told by jeep people to ask on here for some help. Not many GC with the 5.9 produced (only 14k, and only in 98), so there's not much info on it.

Bought it knowing the issue -sporadically wouldn't start-. Drove it home, 8 hours trip without turning off the engine, very nice ride, I love it.
Parked in the garage, and since than, the engine won't start. Cranking happily, but nothing. I've got sparks, I have 5v on every sensor on the block (so I guess not a bad pcm).

The alarm red light on top of the dashboard keeps blinking, no matter what. Key in-out, doors locked/unlocked, key fob opens/closed and so on. Is this the alarm not letting the engine to start?

The previous owner told me that the problem could be in the passenger door module, but never figured out what the problem was. Does anyone now how the alarm works? I'm quite sure it's pretty the same as for the Ram 5.9 Magnum of same years. My pcm is a P56041 539AE

Thanks for reading, and let's make this truck start again!

 

Check and see if you are getting injector pulse. I am not real familiar with the alarms on these myself.....

 

Just walked out to my truck that time (98 Ram with 5.9). Red flashing light is flashing up until the key is inserted. At which point the light doesn't flash anymore even with key removed and multiple key turns or doors opening and closing.

I have never tried this.... But someone told me that there's only 2 wires that run into the engine bay that control any part of the immobilizer. I don't exactly know where they go but allegedly there is a simple snip and twist disable for them.

 

The alarm goes through the CTM

 

What is CTM?

 

I believe it stands for clock timer module. Its a little black box somewhere under the steering column and behind the ash tray. It basically has a bunch of features that pass through it for various reasons. For example it controls the intermittent wiper timing and apparently the immobilizer. I think it also controls the power options but not 100% certain on that one.

 

Central Timer Module. It controls basically everything on the inside.

 

I will need to check if jeeps have this Central Timer Module, first time I hear about it

A friend of mine spent an afternoon trying to diagnose it and came out with "the fuel pump is bad, no pressure in the line". Ok, ordered a new fuel pump assembly and lowered the tank. New pump should be in the box tomorrow.

I was today in the garage to clean a bit around, plugged the battery in the Jeep and that security led light still blinking. Been reading a lot, and it seems like the door lock sensor is what sends a signal to the pcm, telling to shut the alarm (and the no-start feature) off. Anybody has info about this?

I've got the service manual, but the only thing it says is to diagnose with a DRB scan tool. It sounds crazy t me that this pcm can't be triggered to think the alarm is off

 

Supposedly, if you unlock one of the front doors with the key, twice, it *should* reset. I think.

 

Did that probably 1000 times, on both doors and tail door too 😉