Both of your front door lock actuators may be damaged now, but I don't think that was the root cause. The detail that you describe the symtom is great and helpful. According to what you describe, I can only look to the general module (GM) to blame. This is your 540i, right? Spastic operation is not haw actuators normally fail. Actuator failure normally starts as slow operation, then eventually makes a final actuation and fails. The worst is if it fails in double-lock (arrested); getting the door panel off with the door closed usually destroys it to a certain degree.
The GM is responsible for actuating the door locks. It actuates the rears directly and the fronts as a bus message to the door modules which in turn activate the actautors. The fact that they were locking and unlocking in unison, first the passenger side, then the driver's side in concert can only mean they were receiving the command from the GM, via the P-bus. They should have time arrested after a while (32+ times in 2 minutes, I think) then it slows to once every four seconds for three minutes, then back to normal.
Unfortunately, this is not easy to test as it is not possible to identify the bus message. The fact that the rear door locks did not participate in this symphony tells me that it's not a malfunction of the driver's lock cylinder microswitches (water sometimes causes these to malfunction), or the trunk lock microswitches (the wires get damaged in the rubber boot between the trunk lid and body), or the central locking button in the center console (loose connection or liquid intrusion); otherwise all door locks would have participated. If it was isolated to the passenger door, I would suspect the passenger door module.
I'm not sure about the noise coming from the center console area. I'll have to think about that one.
How is the state of health of the battery? If battery voltage dipped while cranking, it may have induced a malfunction in the GM. I would start with a battery reset for about 15 minutes and see if it corrects itself. If the problem persists, the likely canduidate would be the GM. It's the only module that has the ability to cause this scenario as you describe.
If I think of anything else, I'll let you know. Good luck.
The GM is responsible for actuating the door locks. It actuates the rears directly and the fronts as a bus message to the door modules which in turn activate the actautors. The fact that they were locking and unlocking in unison, first the passenger side, then the driver's side in concert can only mean they were receiving the command from the GM, via the P-bus. They should have time arrested after a while (32+ times in 2 minutes, I think) then it slows to once every four seconds for three minutes, then back to normal.
Unfortunately, this is not easy to test as it is not possible to identify the bus message. The fact that the rear door locks did not participate in this symphony tells me that it's not a malfunction of the driver's lock cylinder microswitches (water sometimes causes these to malfunction), or the trunk lock microswitches (the wires get damaged in the rubber boot between the trunk lid and body), or the central locking button in the center console (loose connection or liquid intrusion); otherwise all door locks would have participated. If it was isolated to the passenger door, I would suspect the passenger door module.
I'm not sure about the noise coming from the center console area. I'll have to think about that one.
How is the state of health of the battery? If battery voltage dipped while cranking, it may have induced a malfunction in the GM. I would start with a battery reset for about 15 minutes and see if it corrects itself. If the problem persists, the likely canduidate would be the GM. It's the only module that has the ability to cause this scenario as you describe.
If I think of anything else, I'll let you know. Good luck.
