Power sliding door on driver side of car will not remain open. It closes immediately after opening!
Just a guess but check the door track and opening for an obstruction that would prevent the door from opening completely. If it can’t open all the way it probably reverses and closes.
@davepsinbox_157004 is right. When there is mechanical resistance the door will reverse when in the closing action. I’m not sure about opening action. I do know however that if there’s low voltage to or at the door motor, it will reverse. This happens when I start my van while the door is moving. I’ll check my van after work and see if it reverses when opening when I get home from work and let you know.
That may be a sign that the TIPM is beginning to fail.
TBH, I’m not either, it just seemed to make sense.
And I totally forgot to check.
Ok, I checked this morning. Resistance during closing mode causes door to reverse. Resistance during opening mode causes door to stop. So in the OPs case it is probably opening all the way and then closing. There are a number of contacts on the door and door frame. Might want to try and clean them. Then I would check the switches. One by the door and the other on the overhead panel. Then I would check for shorts in the door closing circuit. Then I would consider @Tester idea of BCM. I have had instances where the doors would not open electrically with any method. After cycling the key they would then function properly.