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Discussion Starter #1
Replaced my 2011 LAF engine that threw a rod with another 35k mi 2011 LAF engine and I can't get it to crank.

This is an extra car and I did a nice slow & easy install and I was extremely systematic and thorough. The first thing I did was disconnect the battery and remove the ECM and put it in a safe place for the several weeks long job.

I'm not getting a signal to the starter relay from the ECM. I can jumper pins 30 and 87 on the starter relay and get it to crank, but not start. I have ohmed out the crank and cam position sensors from the ECM connector. The only thing I can't seem to verify is the low reference through the transmission internal mode switch. It does not show continuity when in park, but also does not seem open either. It always shows a momentary ohm reading and then quickly goes to open.

All of the sensors and the ECM are the same and there is no reason the ECM would know the engine has changed so I am pretty baffled as to why it won't crank.

I have checked all fuses and relays, rechecked all connectors, wiggled wires to no avail. I have 15 pages of wiring diagrams and am out of things to check.

Does anybody have any constructive ideas I may have not that of?
 

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I would suspect a neutral safety switch or linkage out of position possibly moved during the R&R of the engine. Assure that the transmission is actually in the park position while attempting to start.
 

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Discussion Starter #3
That was the first thing I checked. The lever on the transmission is in park. I hooked up an ohmmeter to the neutral safety switch pin on the ECM connector and shifted back and forth to park. I do get an indication when it goes into park, but it is not a direct ground. It's called a low reference and goes thru the ECM which gives it a different indication.
 

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Was there any resolution to this? I'm in the same boat were the ecm isn't sending any voltage to the starter solenoid when turning the key.
 

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Have you checked all your fuses under the hood and inside the cabin? Are your grounds testing ok back to the battery from the engine and trans?
 

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Swap around a known working relay also.
 

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Have you checked all your fuses under the hood and inside the cabin? Are your grounds testing ok back to the battery from the engine and trans?
After posting this I noticed I pulled the wires out of the power steering control module connector when dropping the engine cradle. I'm guessing it took down part of the CAN network that the TCM is on. I'm about to replace the connector, so we will see if my supposition is correct.

 

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Definitely causing a problem.
That's when a scan tool that reads U codes comes into play, it would have shown communication issues.
A shop level scan tool that reads all the P, B,C and U codes is more important that a socket set today doing your own work.
 

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I have a Snap on Modis, Verdict, and an OTC Genisys and I was getting no-com codes. My fear was I left something disconnected that wasn't apparent. My much bigger fear was that the junk yard transmission I put in had a bad TCM that was bringing the network down.

I replaced that connector, and it started up just fine, no codes other than the good ol' P0420 because this car EATS oil.

Interestingly enough it looks like, what I assume are low speed and high speed com network wires, the tan and tan and black can be swapped around and still communicate fine. Or I just got lucky.

 

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Discussion Starter #11
I found my issue was that I connected one of the engine ground wires to the starter. I was several weeks after I pulled the engine when I replaced it and kinda forgot where it went. It was very interesting because it seemed like it fit perfectly where i put it, but it should have been just to the side of the starter bolted to the engine. Normally wires will only lay up nicely where they belong, but this was an exception.
 

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I found my issue was that I connected one of the engine ground wires to the starter. I was several weeks after I pulled the engine when I replaced it and kinda forgot where it went. It was very interesting because it seemed like it fit perfectly where i put it, but it should have been just to the side of the starter bolted to the engine. Normally wires will only lay up nicely where they belong, but this was an exception.
I've done that before. I pulled an engine out of an early 2000's Ford Escape, planning on putting a junk yard motor in after a few days, but ended up blowing out my knee and having surgery,and I didn't touch it for over a year. It took a long time to figure that one out. It didn't help that I was putting in a engine out of a Taurus, so I had to swap the Escape timing cover, valve covers, oil pan, upper and lower intake, ect. over.
 

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One more note to people encountering this thread in the future.

I had a super hard time getting the steering angle sensor to reset. I did it several times on the OTC Genisys then on the Snap on Verdict, and one final time back on the Genisys before it finally cleared. Not sure what the deal was with that

It also shifted pretty harshly till I did an adaptive learn reset on the transmission.
 
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