Well, Hoping someone might have some idea of where to start. My Disco died on my way to school friday. I got a CEL while driving and it immediately shut down and would not start again. I caught a ride to school and at lunch was going to have it towed to a shop ( when I tried to start it it wouldn't even try to turn over) I went to drop the keys in it at lunch and tried to turn it over. It started right up, no CEL, no issues. I drove it home (about 10 miles) and exiting off the freeway it shut down again no CEL this time and would not restart. This time it at least was trying to turn over it just wouldn't fire up. I got it towed to my house bought a scan tool so I could pull up the historical CEL it threw the first time. There was four codes one was for the antitheft signal, two were for MAF related issues, and One said communication issues between computer modules. I assume it is this last one causing me issues. I am charging my battery now, and plan on trying to start again this afternoon and look at the realtime data, although I'm not sure what exactly to look for... Any ideas?

 

Code numbers will help. Battery needs to be 100%.

Without codes, it sounds like a bad Crank Position Sensor (rear of engine, driver's side), when they start to go, can die under way, and when try to crank, no spark. When cool off (by nature or water poured on it) they crank back up.

One el-cheapo test is to run truck until this happens, and pull off a plug wire, attach to spare spark plug, lay on manifold, crank and watch for sparks.

You may also have a battery problem which makes alarm think you are trying to steal the car, battery that goes dead while vehicle locked is a bad thing.

 

Your battery voltage was to low.
Charge the battery, then have the battery and alternator tested.
Computers need close to 100% power to work right.

 

Very true, the alternator cold be just barely putting out, which will be just enough turn off the battery warning light, but not keep up with demand of the fuel pump, heater, etc. So if you charge it up, this will happen again if alternator is not putting out what it should (13.8 - 14.4 at idle, no load, turn on every thing and should still be above 13.2)

 

Mine was a bad battery and crank position sensor....

 

cool ill check on that first and see what happens

 

the battery was low because i had the flashers on for a few hours while i was stranded. I got it charged and all was well. Turns out it was the CPS. thanks so much for the tip, i wasn't quite sure where to start. I verified with a scan tool that shows live data. I started it up and watched rpms from the sensor. Let it run untill it heated up and died again and watched rpms as I tried cranking it they were a big fat zero. I also heard you can back probe the injectors with a logic probe and look for the alterating red/ green lights for normal operation of the cps, but this way seemed easier and i didn't have a logic probe on hand. Thanks again for the tip, I'll be installing the new sensor tomorrow or sat and should be back to causing trouble

 

The injectors run off of the cam sensor, the spark plugs run off of the crank sensor.

 

Josh, what about your other codes, like the MAF codes, have you cleared then and have they come back.
As for the injectors, the cam sensor does have some responsibilty for helping the ECU keep the injectors timed, but the engine will run with out that sensor even plugged in so rule it out for now.
As first mentioned, you and us need actual fault code numbers so you can stop guessing and we can help you get it fixed.