pokitMeter worked very well in this instance. The power back door motors are driven by an ECU in the back door. Jam protection is provided in a couple of ways, one of which is measuring motor speed. If motor speed is too high or too low, judged by comparing a 12 V pulse to an internal specification, the ECU disables the power door. In this case, I had an intermittent fault where the ECU wasn't receiving a pulse from the left motor. I backprobed the pins for the pulse circuit and was able to confirm a very dirty signal in comparison to the pulse circuit on the right motor. Also noted at times there was no pulse at all, meaning some internal fault in the motor itself.
pokitMeter was useful in this case because I was able to watch remotely, outside the vehicle, without any wires getting in the way. pokitMeter is small enough that I simply left it hanging from a magnetic hook inside the rear door while I manually operated the door for the test.
Please sign in to leave a comment.