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Intermittent OBD2, Intermittent P0741, Trans solenoids buzzing when commanded on
Car is a 2007 Hyundai Santa Fe 2.7L A/T without 4WD
Posted here a few weeks back about an intermittent P0741 and no data-link communication.
My SnapOn Modis cannot communicate with the car, but I was able to get Hi-Scan Pro working through CASCADE which gives me limited capability but does allow me to command solenoids and relays on which is a great help. Sometimes it works on the first try, other times it takes a while, cycling the key, jiggling some wires, I haven't been able to find a concrete way to get it to always work yet.
When I command ANY solenoid on for the transmission it emits a buzzing noise but if I supply 12V at the PCM connector for the solenoid pack positive (PCM disconnected fully) and jumper my ground control wire to any of the 5 grounds on the PCM connector (C30B) I get a single solid click. When commanding any solenoids on the ECM I get a solid click so believe this is isolated to the PCM.
Duty cycle when buzzing is 50% but the waveform is a rapid spiking from 0-100, duty cycle when the PCM is removed from the equation is 100%.
I have a spare PCM on hand with the numbers matching and tried swapping over to that and the issue persists so wondering if it could possibly be something else causing this.
Something interesting to note, I'm able to read voltage when checking from battery positive to the ground-control solenoid wires when they're not commanded on ONLY when the key is on as well as continuity to ground only when the key is on.
Checked 5V reference on MAF/IAT connector and got a solid 5 Volts.
I had my power probe in driver test mode and it read a minimum voltage of 0.05V and max of battery voltage but the numbers skip around rapidly and I don't get a solid green light/noise indicator so it seems like it's having issues pulling to ground fully, maybe some corrosion somewhere?
Any thoughts on maybe where to go next, just start unplugging things?
I have the car for a few days so I can test suggestions this time around, thanks!
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