The vehicle's original PBCU was sent to Beckmann for evaluation before purchasing the remanufactured unit. Nothing was found to be out of spec on that original unit; however, Beckmann did advise that their tests covers about 98% of the unit and the possibility exists that there is something they are missing. The reman unit that Beckmann sent was inspected and found to be fault free before shipping.

As for the flap actuators... the entire heater box, which includes, well, everything (including evaporator, heater core and flap actuators) was renewed with a new unit obtained from M-B. Installation of the heater box is basically just a plug and play procedure... with the exception of the evaporator and heater core temp sensors, nothing is transferred from the old heater box; all wiring harness connectors have a dedicated shape that cannot be installed in a wrong location. All vacuum line positions were carefully notated before removal of the original heater box; all lines were installed in their proper positions on the new heater box; proper positioning was reconfirmed using the factory line diagram.

The instrument cluster was inspected with the HHT and no provisions are available for changing the cluster's version coding.

As for the PBCU version coding using the HHT, the choices are simple: chassis choice of 201 or 129 and serial interface K1 and K2. All options have been tested, with no difference in results.

I'd gladly use the PBCU pulled from the donor SL but the LCD on that unit is damaged.

Thanks for the wiring diagrams; I'll check the voltages.