No Spark, no injector pulse, no fuel pump

[mbaker]

I have a 96 Grand Cherokee. I parked it last night and then went back out this morning to start it and...no dice. There is no spark, no injector pulse and the fuel pump does not run. The engine will crank just fine. My mechanic hooked his diagnostic computer to it, and it said 'no communication'. In the manual it said that this might be caused by a basic vehicle computer failure. The problem is, that I can't find anything that Jeep actually calls 'the computer' in any of the manuals (including my Chilton's Manual). There is a Powertrain Control Module (PCM), an Engine Control Module (ECM), etc. But which is the 'computer'? I found a silver, aluminum box mounted to the right side of the firewall behind the coolant reserve bottle. I removed it and took it to two parts stores, and neither could match it up with anything. It has a bunch of numbers on it, like JJ700GWR, P6041, T1925, ZBSAA and a large 172. On the mounting bracket for this device is the number 56027599. Nobody seems to be able to find these numbers. Also, the ECM is apparently located behind the dash and has some of the air conditioning or heater ductwork ncorporated in it. Is either of these devices 'the computer', and would either of them account for the problems I am suddenly having? This Jeep has 199000 miles on it, but it was running absolutely perfectly before this happened. Fortunately, I got it the whole way home into my driveway before it had problems.

[tjganger]

i have an 88 cherokee the ecu is what you need as far as i know i have the same problem but my fuel pump is working as for where the ecu is it should be under the drivers side of the dash as long as it is in the same location