Genuine Volvo Part # 31341090 (31314525) - Parking Aid Control Module. Control Unit. Assist, Rear, Front. Fits S60, S60 Cross Country, S80, V70, XC60, XC70. Ships from Volvo Wholesale Parts Direct, San Luis Obispo CA Apr 21, 2010 · The control module checks that the camshaft is in the correct position in relation to the position of the crankshaft. If the position of the camshaft is incorrect, the control module will adjust the adaptation for the camshaft. Diagnostic trouble code (DTC) ECM-643A or ECM-644A is stored if the adaptation becomes too great. Substitute Value. None. Why does a Volvo S40 AC switch on and off intermittently by itself, even though the climate control module has been replaced? Have a Volvo dealer access the CEM with a scan tool to determine if there was a loss of communication with the control head. To assist in the process, a function called "Control Module Adaptation" has been included in VADIS. This mode is useful when the car is new, the gearbox, valve body or TCM have been replaced, or anytime you want to be sure that the transmission is fully adapted.