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i got a 2012 mustang 3.7l with a 6r80 transmission that is giving problems. several shift solenoid/tcc solenoid codes but also p0657 actuator supply voltage code. trying to test this code alldata give no info about. looking at wiring diagrams on alldata and google it looks like pcm has internal relay to power solenoids but calls it a buffered power supply. i have 12 volts on it checking with a power probe but when load testing it with just a parking light bulb it will not light the bulb and shows voltage drops down to around 1 volt. load testing the wiring shows wiring good from pcm to transmission connector. so my question i guess is what is a buffered power supply and what voltages should i be seeing when before i replace the pcm.
The only relay I see in the attached diagram is in the battery junction box. Which wire are you testing that cannot support enough current flow to light a bulb?
i was check pin 12 on the transmission that at the pcm side showed vpwr. but after doing some more research and checking with a buddies mitchell it showed a trouble tree for the code(which alldata doesn't have) and that showed pin 7 at the transmission to be the power supply for the solenoids. after finding that i found no power coming from pcm but when i powered that wire up the transmission is shifting fine now. thanks for the reply.
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