Lars, The two units in the rear of the car CLP/SLS (Central Locking Pump/Security Locking System) which is a single unit with the air hoses attached, and the tow away alarm do not require programing. Simply interchange between like models. Coupe to coupe, roadster to roadster. NO programing.

The SKREEM (Sentry Key Remote Entrance Module) located under the dash behind the instrument cluster on our left hand drive cars requires programing. The SKREEM interchanges info between several other devices and must be programed to match the PTCM (Power Train Control Module). The PTCM is often referred to as the ECU, but in Chrysler terminology it is the PTCM.

Is it possible one of the air/vacuum lines has a crack which allows the system to work sometimes, but not at others? Perhaps test with a pressure gauge from the rear of the car and open close the doors to see if pressure leaks out.