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Home >> Volvo >> 2004 >> XC90 Base, AWD >> Repair and Diagnosis (Single Page) >> Electrical >> Body Electrical >> Central Electronic Module (CEM) - Diagnostic Trouble Codes - 7 Of 7 >> CEM-6D0F: Relay, Child Safety Blocking. Signal Too Low. Intermittent Fault (2003-2004) >> Signal Too Low. Intermittent Fault >> Checking The Control Module For Open-Circuits
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Checking The Control Module For Open-Circuits

Remove relay 2/120.

Check the driver circuit for the relay coil for an open-circuit as follows:

Measure the voltage between the points #1 and #2 in the relay socket. For more information about open circuits, see:CHECKING WIRING AND TERMINALS. PERMANENT FAULT

Activate the relay with the switch child safety lock, for windows rear doors, on the driver's control panel (activated relay LED on).

HINT: Voltage between #1 and #2 shall be battery voltage. 

If the value deviates significantly, check voltage between #2 and battery voltage as well as between #1 and ground. Both shall be equal to battery voltage. Check for open circuits according to: CHECKING WIRING AND TERMINALS. PERMANENT FAULT

Do not forget to check that the power supply to the control module is OK.

Other information 

Fig 1: Identifying Voltage Display
GLL101041Courtesy of VOLVO CARS CORPORATION
Fig 2: Identifying Relays
GLL104067Courtesy of VOLVO CARS CORPORATION