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Home >> Volvo >> 2013 >> XC90 Base, FWD >> Repair and Diagnosis (Single Page) >> Electrical >> Body Electrical >> Central Electronic Module (CEM) - Diagnostic Trouble Codes - 2 Of 7 >> CEM-1A5C: Communication With The Upper Electronic Module (UEM). Signal Missing (2003-2004) >> Signal Missing >> Checking The Function Of The Upper Electronic Module (UEM)
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Checking The Function Of The Upper Electronic Module (UEM)

Check that the upper electronic module (UEM) is powered by switching on one of the rear reading lamps.

Fig 1: Identifying Rear View Mirror
GLL107626Courtesy of VOLVO CARS CORPORATION

Does one of the rear reading lamps light? 



HINT: After carrying out the repair, check that the fault has been remedied. 

Fig 1: Identifying Ignition ON
GLL101051Courtesy of VOLVO CARS CORPORATION
Fig 2: Connecting Connector
GLL101069Courtesy of VOLVO CARS CORPORATION

Does one of the rear reading lamps light?