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My Dad and I swapped a motor from a 2008 Silverado into a 2009 (4.3L V6)
Both motors ran before swap, one with a bad bearing (2009) and the other with a bad transmission (2008). The Bad transmission (2008) is now in the 2009 truck and were experiencing 5v system failure. I've watch the video posted where he trouble shoots this on a Cadillac and it helped up a lot, but what we're trying to come up with now is a diagram for the 5v electrical system, or a list of sensors on the 5v-1 system so we can trace whats going on.
Currently have DTC's
Current - P0641
Pending - B2AAA
Pending - P0107
Pending - P0452
Tested for 5v at ECM pin 13 (Grey) and there's 4.85v (5v-1)
Tested at pin 53 (Grey) and that had 4.95v (5v-2)
Tested at pin 54 (PU/WH) and that had 4.95v (5v-2)
Tested at Throttle body Grey pin had 4.95
Test at Map, a/c pressure and Fuel pressure sensor and there's less than 1v
We have slowly moved the harness around and watched a multimeter that was alligator clipped to pins and not seen any change in voltage.
During the engine swap, the engine wire harness was ziptied up to the firewall out of the way of the motor and transmission to avoid and crushing or tearing. I'm just wondering if this in turn created our problem.
Truck runs and drives but with Engine Low Power message and does so poorly.
P0641 sets for a problem with the 5v ref 1 circuit.
MAP sensor, FTP (fuel tank pressure), A/C pressure sensor, accelerator pedal position sensor 2, engine oil pressure sensor and camshaft position sensor according to what I'm seeing on All Data
Got to see if all those sensors are on the same5 volt reference. I don’t think you have a shorted sensor because you have the 5 volts at the computer. So trace the map sensor wire back and see if you find any corrosion
If your voltage reading at the MAP and A/C pressure sensor was less than 1.00V but not 0V, then I'd suspect a resistive short to ground somewhere. While you're disconnecting the 5V Ref. 1 sensors one at a time, check their connectors for water or coolant an dry them out as needed.
Solved the issue tonight, the pigtail from the oil sender was pinched between the block and the transmission. I appreciate all the responses and this diagram is what led to us finding the issue. Thanks a bunch!
