Hi all, just been reading all the threads about crank but no start and it seems to be a common issue. Am I right in the general consensus it is more than likely either Crank Position Sensor, RCM, or Fuel Pump/Relay Issue?

My crossfire has been sitting for a while without starting (maybe 8 months) and noticed the battery was dead. Replaced the battery, but now wont start. Remote works fine, so didn't think it was a security system fault.

I don't have a merc type scan tool, just a little generic one, and shows no codes. Nothing is showing on the dash when I try to start, and I have replaced the CPS with a new bosch one I bought for the donor (eventual 5.0lts swap from my W163 ML500) which looks like it's the same part. Still no start. Also when I tried to start a couple of times, I can smell the fuel getting delivered so pretty sure the pump is working. Checked the fuses, and can't find any blown.

I haven't removed the RCM yet, or the relay, but wanted to know if there's something else I could be checking. I will check the CPS with the multimeter when I have someone else there to crank while I watch the output or remove it and check the ohms, but the only strange thing I see happen when I try to start is the light on the switch for Rear Spoiler flashes and when I replaced the battery, the spoiler raised. I know it's difficult without a scan tool, but a lot of the recommendations on here for scanners, date back to 2008.

Finally, if the CPS is sending out the correct volts (can someone tell me what should I expect from the CPS while cranking?), then should I unplug the RCM and remove and check, or is there a step between I could try? I saw a video of an slk320 not starting due to a bad Cam Position Sensor or bad connector to this. Thoughts? Oh also have the 3000+ page crossfire service manual if anyone wants it. Not sure if it's on here already.