If the driver's door actuator is good, you should be able to sync the remotes. Right?
It does sound like a wiring/grounding problem for part of the circuit. Since your front passenger lock can trigger the rear and the trunk, it sounds like it could be a problem at or near the BECM. Check for moisture under the passenger seat near the BECM. I think that leaky heater core o-rings are capable of flooding the area near the BECM and causing strange problems.
It does sound like a wiring/grounding problem for part of the circuit. Since your front passenger lock can trigger the rear and the trunk, it sounds like it could be a problem at or near the BECM. Check for moisture under the passenger seat near the BECM. I think that leaky heater core o-rings are capable of flooding the area near the BECM and causing strange problems.