2020 Mazda CX-5
“Window goes up in one inch increments”. Vehicle came in with no window express up and down functions and goes up in one inch increments. No history on vehicle, just that a prior tech attempted the auto express relearn and a battery disconnect “Battery Jesus”. No codes related to window operation and there is almost no scan data for this system. I once again re attempted the auto relearn, but there was no change. I removed the door panel and found no evidence of tampering or aftermarket parts. My first step I went with using a current clamp and since the left rear motor was the same part number I measured current at both doors and swapped the motors.
Since a binding regulator and or window run, would cause increased effort from the window. Current should increase due to the demand not he motor. However when the left front and left rear motor are swapped. Both motors don't show excessive current and actually the left rear motor has slightly more.
In this capture, I am back probed at both Hall effect signal wires coming out of the motor. The top waveform is the live vehicle. The bottom capture is also the live vehicle (but of the vehicle fixed and what it should look like. As you can see both circuits only display each time I hit the button to go up.
Here is my Microsoft whiteboard for this vehicle. Which includes my captures along with some notes. Since there were no codes I found some info in Alldata directing me to inspect the hall effect circuits after load testing each circuit to and from the power master switch. SI states that if the waveform is abnormal to replace the motor, and then after that replace the power window switch. However the front left and rear left were swapped which rules out a motor issue. No where does it say check some of the other circuits coming out. Since the left rear motor has the same exact inputs I compared and found that the violet wire should have B+ coming out of it and it didn't. I think applied power to that circuit and all window functions came alive. Upon removal of the switch I found corrosion and damage to the board. Switch was replaced. Vehicle fixed!