ECM cuts out after warming up

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MatthewGoff

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I replaced my ECM with a junkyard one after mine fried. ran great other than the ABS light was flashing which i have determined it to be the fact that my truck does not have ABS hubs. But, the truck still shuts off after warming up.

I bit the bullet and actually took it to a mechanic with a mack daddy computer, just for ***** and giggles since im at the end of my rope.

we waited a while to see if it was gonna do its thing and it finally did while he still had his magic box hooked up. When it dies it loses power to the ECM, his computer lost comm's and we've come to the conclusion that my junkyard ECM with matching number is just that, junk.

the power feeding to the ECM stays connected going to the fuse 19 in the TIPM when the ECM cuts out. while at rest the battery voltage is around 13v, while its running its at 14v. is this too high? it also feeds that 14v into the ECM as well. it seems a little much if you ask me. so before i go buy a refurbished ECM im trying to track down the grounds and 12v supplies to the computer.
 

kad

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Automobile electrical systems are only nominally 12 volts. Resting voltage fully charged is between 12 and 13 and running voltage at the battery should be right around 14, that's normal.

-K
 
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MatthewGoff

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Automobile electrical systems are only nominally 12 volts. Resting voltage fully charged is between 12 and 13 and running voltage at the battery should be right around 14, that's normal.

-K
thanks, didnt know if it was something that could be detrimental to the ecm, i seen on the pinout for the black plug going into the ECM that there was a 5v going in and didnt know if i should have a lower voltage going in to the ECM. never could get the fuse B to read a 5v like it says in the pin out but maybe im looking at it all wrong.
 

kad

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thanks, didnt know if it was something that could be detrimental to the ecm, i seen on the pinout for the black plug going into the ECM that there was a 5v going in and didnt know if i should have a lower voltage going in to the ECM. never could get the fuse B to read a 5v like it says in the pin out but maybe im looking at it all wrong.

The ECM and a lot of the sensor network does run on 5v, but having 12-14 at the battery is normal.

-K
 
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