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Home >> Volvo >> 2003 >> XC90 Base, AWD >> Repair and Diagnosis (Single Page) >> Electrical >> Body Electrical >> Control Module - Signal Specifications >> Signal Specification, Upper Electronic Module (UEM) (2003-2014) >> Signal Description, Upper Electronic Module (UEM) >> Upper Electronic Module (UEM)
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Upper Electronic Module (UEM)

Fig 1: Identifying Connector (F) Terminals
GLL104034Courtesy of VOLVO CARS CORPORATION

Connector A, terminals #A1-#A22

The following values are measured between the relevant terminal in column 1 and terminal #A20 (signal ground) unless otherwise stated.

NOTE: Check the ground terminals before starting to take readings with the breakout box.

U = DC in volts (V).

Ubat = battery voltage in volts (V).

Ulow = voltage near 0 V.

Terminal, breakout box  Terminal, control module  Signal type  Ignition off 
Active/not active 
Ignition on 
Active/not active 
Miscellaneous 
#1 #A1 Power supply Ubat Ubat -
#2 #A2 Third row reading lamps, control signal (XC90 only) Ubat /0 V Ubat /0 V -
#3 #A3 Communication cable control modules (HS-CAN) 2.5-3.5 V 2.5-3.5 V During communication.
#4 #A4 The front right reading lamp and general lighting, control signal 7-9 V/0 V 7-9 V/0 V Active when the right front reading lamp or the general lighting is activated.
#5 #A5 Communication cable control modules (MS-CAN) 1.5-2.5 V 1.5-2.5 V -
#6 #A6 The front right reading lamp, signal supply Ubat /0 V Ubat /0 V Pulse width modulation (PWM) signal.
#7 #A7 Rear left reading lamp, signal supply Ubat /0 V Ubat /0 V Active when the left rear reading lamp or the general lighting is activated. Pulse width modulation (PWM) signal.
#8 #A8 Extended X-supply Ubat /0 V Ubat /0 V The power supply to the sun roof logic, mirror lamps in the sun visor, rain sensor, buttons for the headlining lighting and certain button lighting.
#9 #A9 Cargo compartment lighting (V70, V70 XC) / Third row reading lamps (XC90), power supply Ubat /0 V Ubat /0 V Pulse width modulation (PWM) signal.
#10 #A10 Movement sensor (MMS) or movement sensor (IMS), power supply, (IMS replaces MMS for XC90 from and incl. model year 2012) Ubat /0 V Ubat /0 V Supplies power to both MMS or movement sensor (IMS), (IMS replaces MMS for XC90 from and incl. model year 2012).
#11 #A11 Control module power supply Ubat Ubat -
#12 #A12 Control module power supply Ubat Ubat -
#13 #A13 Rain sensor, data signal - - -
#14 #A14 Rear right reading lamp, signal supply Ubat /0 V Ubat /0 V The signal is active when the button for the lamp is not pressed in.
#15 #A15 Rear left reading lamp, control signal Ubat /0 V Ubat /0 V The signal is active when the button for the lamp is not pressed in.
#16 #A16 The front left reading lamp and general lighting, control signal 7-9 V/0 V 7-9 V/0 V Active when the left front reading lamp or the general lighting is activated.
#17 #A17 The rear right reading lamp, signal supply Ubat /0 V Ubat /0 V Active when the right rear reading lamp or the general lighting is activated. Pulse width modulation (PWM) signal.
#18 #A18 The front left reading lamp, signal supply Ubat /0 V Ubat /0 V Pulse width modulation (PWM) signal.
#19 #A19 General lighting, signal supply Ubat /0 V Ubat /0 V Pulse width modulation (PWM) signal.
#20 #A20 Signal ground U~U=low U~U=low -
#21 #A21 Serial communication (Volcano lite) 0 V-Ubat 0 V-Ubat The voltage is 0 V - Ubat during communication. Ubat is the default.
#22 #A22 Movement sensor (MMS) or movement sensor (IMS), (IMS replaces MMS for XC90 from and incl. model year 2012), data signal Ubat Ubat Communication with both MMS or movement sensor (IMS) in XC90, (IMS replaces MMS in XC90 from and incl. model year 2012).