Fried ECM?

black07

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Oct 8, 2011
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Hey guys, need some help. I had a crank sensor wire ground out on my exhaust manifold, now the truck won't start. Fixed the wire and replaced the sensor and still nothing. Checked all fuses and known of them are blown. Used a test light and checked for power, didnt have any power at the crank harness or the cam harness. Didn't have power on the connector to the alt. either. I did have power to my maf sensor and fpr harness. Didn't get to check anything else yet. So my question is, could the ECM be fried even if it didnt blow a fuse? Is there anyway to actually check it? Any help would be great.
Thanks
 

paint94979

Beer Nazi
Sep 18, 2006
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do you have a V2? You can always try and see if EFI Live can detect your ECM? Maybe try and log actual fuel pressure?
 

black07

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Oct 8, 2011
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Yea I have a v2. I can try that, just need to find time. It only cranks for 5 seconds and then stops. Before it died the fuel pressures were good. It has two new regulators on it. It seems electrical.
 

duratothemax

<--- slippery roads
Aug 28, 2006
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If it cranks for a couple seconds then stops, that means the ECM isnt getting a good crank signal.

The ECM will cut the starter off (even if you're still holding the key to start) if it doesnt pick up a valid crank signal within 2 seconds or so.

Get your V2 and see if it registers RPM when cranking. Or if there are any codes.
 

black07

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Oct 8, 2011
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If it cranks for a couple seconds then stops, that means the ECM isnt getting a good crank signal.

The ECM will cut the starter off (even if you're still holding the key to start) if it doesnt pick up a valid crank signal within 2 seconds or so.

Get your V2 and see if it registers RPM when cranking. Or if there are any codes.

Ok, if it comes up showing no rpm, is that an ECM problem?
 

bluecollar

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Feb 28, 2012
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I had a cam sensor short out and ground that circuit.. Had no rpm signal also.. Replaced cam sensor and all was good.. I knew when I unplugged the cam sensor and then had power to the crank sensor that was the problem.. I realize this probably isn't ur issue but just throwing it out there.. Good luck!!
 
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durallymax

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Apr 26, 2008
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x2 on what Ben and Paint said. Make sure you can communicate with ECM to begin with, then see if you are getting a good signal.

If communication is not there for ECM, pull the connectors and test the pins that supply power both constant and keyed.

If you can find a decent DMM it would be much quicker and more reliable than a test light.
 

black07

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Oct 8, 2011
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Ok, ill try everything mentioned here. Thanks for your guys input. Worst case ill just have to try to find a used wiring harness and try that and an ECM since no one around here has one I can try.