Originally Posted by pizzaguy

It means that the ECM must be powering up along with the Fan module OR that NEITHER are powering up. Given that the only thing needed to power up the fan module is the ignition switch, and that you have battery power for lights - I'd say it's fair to assume that the ECU is powering up and that the RCM is fine.

A real "no crank" that is, no engagement of the starter, given what we know, would seem to be to be one of these:

1) Clutch switch open (does not exist on automatics)
2) Bad pulse module (rare but it happens)
3) Defective ECM (don't think I've ever heard of one failing, least not in this way)
4) SKREEM module-related issue (disconnect battery 30 seconds, reconnect, if the starter engages and car starts and stalls three times, then you get no starter again - you have a SKREEM-related issue, PERIOD. End of discussion. ).

Here's a trick: Turn headlights on (make someone stand in front of the car so you can SEE the ligths shine). Hit key to start - if the lights dim a lot but you get no starter engagement, you have a fundamental issue (bad battery, really bad battery cable connection, etc.) - should be easy to find that one.