Nope, that does nothing, after clearing codes, turning off engine, turning back on, they come back.

 

Continuing this never ending story.
DTC B2725
"The system constantly monitors the voltage on switch signal circuit.
If the system detects a voltage level under 0.3 volt or greater than 0.75 volts for 60 seconds, the DTC is logged."
Is that "Mode switch supply voltage" that is being tested?
If it falls below 4.7 or above 5.75 then it triggers this error?

Also "Mode switch return voltage" is constantly 0.27, it is never 0, not sure if that is a problem, maybe intended feature.
Somewhere circuit is closed with resistor. Checked switches they are fine.
It does change whenever buttons are pressed and circuits are closed with different resistances.

I forgot to measure voltage that goes to "traction control switch", my old head, that will be for tomorrow.
Next step is to tear down passenger side and check "Transfer Case Shift Control Modules" for visible damage(liquid/corrosion/whatnot)

 

Traced cable to BCM, no shorts, cable is fine.
Ripped out BCM, opened up.

Does not look too good.



Got some common household tools:


Nice and gently rubbing resulted in shiny BCM board.



Put it back together, drove around 5 miles.
My TPS reports work now! They did not before.

Service 4W drive error did not show up in dash.
Will drive around some more tomorrow, see how it goes.

Possibly, problem solved.

 

Looks good. Nice work! Btw, dealers service and auto repair shops won't like your post, since they prefer to throw parts at it, at the customer's expense.

 

Looks like water damage.
Sunroof on your H3?

 

TAINTER: sunroof never had much leaks while I owned truck.
I tested tubes and passenger side tube was very slow to drain water, driver side was much better.
Looks like water or condensation of water that oxidised board.
Sunroof has 2 weather seals around it, one can be removed and one that is pressed in.
One that is pressed in, driver side, is defective from factory and is not proper width therefore with some force and right angle(pressure washing) water comes in.
Discovered water dripping trough onstar microphone. Took sunroof off and discovered problem, possibly fixable with glass glue or polyurethane something.

My sunroof if not moving right now, possibly plastic cogwheel is broken. Motor works.
I unscrewed sunroof and positioned in best possible position so that no liquid comes in and lubed with silicon paste everything.
Project for the summer time to remove everything and see what I can do/repair.

 

So for ALL of those words above, I get a YES SUNROOF LEAKING on BCM causing corrosion and shorting .
Fix all of the drain tubes and cut the nipples or it will happen again, and again, and again, and....

 

Few weeks later:
Service 4WD drive was not flashing any more.
B2725 was gone, finally, after multiple ignition cycles, no more!

B2745 still persisted, but this code did not trigger service message(still had once stabilization light show up).

Yesterday got back B2725 and service 4wd drive!
It was rainy outside, ripped out BCM, dry, no moisture, ripped out carpet, nothing, dry(there was substantial rust under passenger feet, so water was leaking before I owned a car, needs wielding).
Will grind down rust spots and repaint, good reason.


Next step is to rip out console/dashboard and see if anything is wrong there.

Something with moisture somewhere, I need to find out all ground points maybe.

Worst case scenario is to buy new BCM, but that is too expensive now, maybe next year. Can live with error messages for now.

 

Did you clean/reseat connections at the EBCM?
Clean and seal connections first! GL

 

No, I have no knowledge about "EBCM", I cleaned/restored only BCM.
Will look into where it is located and rip it apart.

Thank you!