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Home >> Volvo >> 2009 >> V70 >> Repair and Diagnosis (Single Page) >> Electrical >> Motors, Switches, Relays >> Central Electronic Module (CEM) And Accessory USB Unit (AUU) - Specifications, Electrical/Electronic >> Signal Description Central Electronic Module (CEM) (2010) >> Signal Specification
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Signal Specification

NOTE: Signal description for CEM generation 2 (structure week >= 09w46) see SIGNAL DESCRIPTION CENTRAL ELECTRONIC MODULE (CEM) 

All values given below are between the terminals stated in column 1 and terminal #D5 (power ground). This applies unless otherwise indicated in the last column.

NOTE: It is important to connect the breakout box and check the ground connections before starting to measure.
U= DC voltage in volts (V) UAC = AC voltage in volts (V)
Ubat = Battery voltage (V) f = Frequency in Hertz (Hz)
Ulow = Voltage approximately 0 V t = Time in seconds
PWM = Pulse-width modulated signal in % - -
Fig 1: Identifying 76-Pin Connector
GLL155449Courtesy of VOLVO CARS CORPORATION
SIGNAL TABLE

Connector C1 (Green)
Breakout box terminal  Control module terminal  Signal type  Ignition off 
Active/Not active 
Ignition on 
Active/Not active 
Miscellaneous 
#A1 #C1:1 Front right-hand turn signal lamp, power supply U = 0 V U=Ubat /u V -
#A2 #C1:2 Reserve - - -
#A3 #C1:3 Reserve - - -
#A4 #C1:4 Reserve - - -
#A5 #C1:5 Reserve - - -
#A6 #C1:6 Reserve - - -
#A7 #C1:7 Auxiliary light relay, control signal U = 0 V U=Ubat /U=0 V Extra accessory
#A8 #C1:8 Reserve - - -
#A9 #C1:9 Reserve - - -
#A10 #C1:10 Front left parking lamp, power supply Ubat /Ulow Ubat /Ulow -
#A11 #C1:11 Engine coolant level sensor, input signal Ulow at normal level; Ubat at low level -
#A12 #C1:12 Reserve - - -
#A13 #C1:13 Front left parking lamp, power supply Ubat /Ulow Ubat /Ulow -
#A14 #C1:14 Sun sensor 2 (right) - - -
#A15 #C1:15 Reserve - - -
#A16 #C1:16 Reserve - - -
#A17 #C1:17 Electronic power steering module, signal supply Ubat at ignition in position II; Ulow otherwise -
#A18 #C1:18 Reserve - - -
#A19 #C1:19 Front left-hand turn signal lamp, power supply Ulow Ubat -Ulow /Ulow -
#A20 #C1:20 Reserve - - -
#A21 #C1:21 Reserve - - -
#A22 #C1:22 Reserve - - -
#A23 #C1:23 Hood switch Ulow with the hood closed
Ulow -Ubat with the hood open
Pulsed signal, f= 100 Hz
#A24 #C1:24 Reserve - - -
#A25 #C1:25 Switch, washer fluid level Ulow at normal level; Ubat at levels below 1 liter -
#A26 #C1:26 Reversing switch, input signal - - -
#A27 #C1:27 Switch, brake fluid level Ulow at normal level; Ubat at low level -
#A28 #C1:28 Spare - - -
#A29 #C1:29 Reserve - - -
#A30 #C1:30 Reserve - - -
#A31 #C1:31 Reserve - - -
#A32 #C1:32 Reserve - - -
#A33 #C1:33 Reserve - - -
#A34 #C1:34 Reserve - - -
#A35 #C1:35 Communication LIN bus 2 During communication the voltage is 0 V - Ubat BBS
#A36 #C1:36 Communication LIN bus 2 During communication the voltage is 0 V - Ubat WMM
#A37 #C1:37 Brake light switch, input signal Ulow Ulow / Ubat -
#A38 #C1:38 Reserve - - -
#A39 #C1:39 Reserve - - -
#A40 #C1:40 Front right-hand parking lamp, signal Ubat /Ulow Ubat /Ulow -
#A41 #C1:41 Front right-hand parking lamp, power supply - - -
#A42 #C1:42 Reserve - - -
#A43 #C1:43 Reserve - - -
#A44 #C1:44 Engine control module (ECM), waking Ulow Ubat /Ulow -
#A45 #C1:45 15 supply Ulow Ubat -
#A46 #C1:46 Relay, horn, control signal Ulow / Ubat Ulow / Ubat -
#A47 #C1:47 Headlamp cleaning, control signal Ubat Ulow / Ubat -
#A48 #C1:48 Comfort relay, control signal Ulow Ubat /Ulow -
#A49 #C1:49 Communication CAN H
Low speed bus
During communication the voltage is 2.0-3.5 V -
#A50 #C1:50 Communication CAN L
Low speed bus
During communication the voltage is 1.5-2.5 V -
#A51 #C1:51 Clutch pedal sensor, external, voltage supply Ulow U =5 V -
#A52 #C1:52 Clutch pedal sensor, external, signal - - -
#A53 #C1:53 Clutch pedal sensor, external, ground Ulow Ulow -
#A54 #C1:54 Electronic ground U = Ulow U = Ulow -
#A55 #C1:55 15-feed, BCM and accelerator pedal Ulow Ubat -
#A56 #C1:56 Reserve - - -
#A57 #C1:57 Reserve - - -
#A58 #C1:58 Reserve - - -
#A59 #C1:59 Reserve - - -
#A60 #C1:60 Reserve - - -
#B1 #C1:61 Reserve - - -
#B2 #C1:62 Reserve - - -
#B3 #C1:63 Reserve - - -
#B4 #C1:64 15-power supply Ulow Ubat -
#B5 #C1:65 15-power supply Ulow Ubat -
#B6 #C1:66 Reserve - - -
#B7 #C1:67 BBS, power supply Ulow Ubat -
#B8 #C1:68 Front right fog lamp, power supply Ulow Ubat /Ulow -
#B9 #C1:69 Front left fog lamp, power supply Ulow Ubat /Ulow -
#B10 #C1:70 Reserve - - -
#B11 #C1:71 Front washer motor, power supply - - -
#B12 #C1:72 Front washer motor, ground U = Ulow U = Ulow -
#B13 #C1:73 Right high beam, power supply Ulow Ubat /Ulow -
#B14 #C1:74 Left high beam, power supply Ulow Ubat /Ulow -
#B15 #C1:75 Right low beam, power supply Ulow Ubat /Ulow -
#B16 #C1:76 Left low beam, power supply Ulow Ubat /Ulow -
Fig 2: Identifying 76-Pin Connector
GLL155449Courtesy of VOLVO CARS CORPORATION
Connector C2 (Brown)
Breakout box terminal  Control module terminal  Signal type  Ignition off 
Active/Not active 
Ignition on 
Active/Not active 
Miscellaneous 
#C1 #C2:1 Reserve - - -
#C2 #C2:2 Reserve - - -
#C3 #C2:3 Reserve - - -
#C4 #C2:4 Reserve - - -
#C5 #C2:5 Reserve - - -
#C6 #C2:6 Switch right front door, check signal Ubat if the door is open; Ulow otherwise -
#C7 #C2:7 Switch left front door, check signal Ubat if the door is open; Ulow otherwise -
#C8 #C2:8 Switch right-hand rear door, check signal Ubat if the door is open; Ulow otherwise -
#C9 #C2:9 Switch left-hand rear door, check signal Ubat if the door is open; Ulow otherwise -
#C10 #C2:10 Switch trunk lid/tailgate, check signal Ubat if the trunk lid/tailgate is open; Ulow otherwise -
#C11 #C2:11 Accelerator pedal (AP) position sensor, power supply Ulow U = 5 V -
#C12 #C2:12 Brake lamp switch Ulow Ubat /Ulow -
#C13 #C2:13 Trunk lid/tailgate handle - - -
#C14 #C2:14 Reserve - - -
#C15 #C2:15 Reserve - - -
#C16 #C2:16 Reserve - - -
#C17 #C2:17 Communication LIN bus 0 During communication the voltage is 0 V - Ubat -
#C18 #C2:18 Rear right turn signal lamp, power supply Ulow Ubat -Ulow /Ulow -
#C19 #C2:19 Reserve - - -
#C20 #C2:20 Seat belt reminder sensor, rear left, input signal Ulow U = 0-5 V -
#C21 #C2:21 Seat belt reminder sensor, rear center, input signal Ulow U = 0-5 V -
#C22 #C2:22 Seat belt reminder sensor, rear right, input signal Ulow U = 0-5 V -
#C23 #C2:23 Seat belt reminder sensor, passenger seat, input signal Ulow U = 0-5 V -
#C24 #C2:24 Rear right parking lamp, power supply Ubat /Ulow Ubat /Ulow -
#C25 #C2:25 Reserve - - -
#C26 #C2:26 Rear window defroster, control signal Ulow Ubat /Ulow -
#C27 #C2:27 Clutch pedal switch, internal, 75% Ubat Ulow / Ubat -
#C28 #C2:28 Reserve - - -
#C29 #C2:29 Accelerator pedal position sensor, input signal - - -
#C30 #C2:30 Fuel level sensor, pump side, input signal Ulow U = 0.5-4 V -
#C31 #C2:31 Communication LIN bus 2 During communication the voltage is 0 V - Ubat Heartbeat sensor (HBS).
Mass movement sensor (MMS) (only XC60 with Panorama roof).
#C32 #C2:32 Reserve - - -
#C33 #C2:33 Clutch pedal switch 25% - - -
#C34 #C2:34 High level brake light, power supply Ubat /Ulow Ubat /Ulow -
#C35 #C2:35 Reserve - - -
#C36 #C2:36 Rear left turn signal lamp, power supply Ulow Ubat -Ulow /Ulow -
#C37 #C2:37 Reserve - - -
#C38 #C2:38 Emergency brake light, power supply Ubat /Ulow Ubat /Ulow -
#C39 #C2:39 Rear fog lamp, power supply Ulow Ubat /Ulow -
#C40 #C2:40 LIN bridge The voltage is 0 V - Ubat during communication -
#C41 #C2:41 Reserve - - -
#C42 #C2:42 Foldable head restraint Ulow Ubat /Ulow -
#C43 #C2:43 Fuel level sensor, ejector side Ulow U=0.5-4 V -
#C44 #C2:44 Reserve - - -
#C45 #C2:45 15-feed Ulow Ubat -
#C46 #C2:46 Fuel level sensor, ejector side, ground Ulow Ulow -
#C47 #C2:47 Accelerator pedal position sensor, ground Ulow Ulow -
#C48 #C2:48 Fuel level sensor, ground Ulow Ulow -
#C49 #C2:49 Reserve - - -
#C50 #C2:50 Rear left parking lamp, power supply Ubat /Ulow Ubat /Ulow -
#C51 #C2:51 Reserve - - -
#C52 #C2:52 License plate lighting, power supply Ubat /Ulow Ubat /Ulow -
#C53 #C2:53 Switch, lock, tailgate - - -
#C54 #C2:54 Brake light switch, input signal - - -
#C55 #C2:55 15-power supply Ubat Ubat Accelerator pedal position sensor
#C56 #C2:56 Power supply to interior lighting and driver's door control panel Ubat /Ulow Ubat -
#C57 #C2:57 Heartbeat sensor (HBS), Mass movement sensor (MMS), power supply Ubat Ubat Mass movement sensor (MMS) only for XC60
#C58 #C2:58 BCM, accelerator pedal, 15-feed Ulow Ubat -
#C59 #C2:59 Stop (brake) lamps Ulow Ubat /Ulow -
#C60 #C2:60 Reserve - - -
#D1 #C2:61 Reserve - - -
#D2 #C2:62 Right reversing lamp, power supply Ulow Ubat /Ulow -
#D3 #C2:63 Reserve - - -
#D4 #C2:64 Power driver's seat and power passenger seat, power supply Ubat /Ulow Ubat /Ulow -
#D5 #C2:65 Power ground Ulow Ulow -
#D6 #C2:66 Brake light switch, power supply Ulow Ulow / Ubat -
#D7 #C2:67 Tank hatch, unlocking Ubat /Ulow Ubat /Ulow -
#D8 #C2:68 Reserve - - -
#D9 #C2:69 Occupant weight sensor, power supply - - -
#D10 #C2:70 Power supply relay, rear wiper motor - - -
#D11 #C2:71 Trunk lid/tailgate, unlocking Ubat /Ulow Ubat /Ulow Does not apply to the S80
#D12 #C2:72 Trunk lid/tailgate, locking Ubat /Ulow Ubat /Ulow Does not apply to the S80
#D13 #C2:73 Left reversing lamp, power supply Ulow Ubat /Ulow -
#D14 #C2:74 Rear wiper motor, control signal - - -
#D15 #C2:75 Reserve - - -
#D16 #C2:76 Fuel pump (FP), power supply Ulow Ubat /Ulow -
Fig 3: Identifying 76-Pin Connector
GLL155449Courtesy of VOLVO CARS CORPORATION
Connector C3 (Blue)
Breakout box terminal  Control module terminal  Signal type  Ignition off 
Active/Not active 
Ignition on 
Active/Not active 
Miscellaneous 
#E1 #C3:1 Sun sensor, left, ground Ulow Ulow -
#E2 #C3:2 Sun sensor left Ulow U = 0.25-4.75 V -
#E3 #C3:3 Sun sensor 2 (right) - - -
#E4 #C3:4 Reserve - - -
#E5 #C3:5 Reserve - - -
#E6 #C3:6 Reserve - - -
#E7 #C3:7 Reserve - - -
#E8 #C3:8 Hazard warning flasher switch Ulow /Ubat Ulow /Ubat -
#E9 #C3:9 Reserve - - -
#E10 #C3:10 Windshield wipers, Limp-home switch Ubat /Ulow Ubat /Ulow -
#E11 #C3:11 Parking brake switch Ubat Ulow /Ubat -
#E12 #C3:12 Reserve - - -
#E13 #C3:13 Horn switch, input signal Ulow / Ubat Ulow / Ubat -
#E14 #C3:14 Reserve - - -
#E15 #C3:15 Reserve - - -
#E16 #C3:16 Reserve - - -
#E17 #C3:17 Reserve - - -
#E18 #C3:18 Collision Normal, f = 10 Hz, PWM = 50%.
Impact registered, f = 250 Hz, PWM = 50%, for up to 5 seconds.
-
#E19 #C3:19 Courtesy lamp Ubat /Ulow Ubat /Ulow -
#E20 #C3:20 Reserve - - -
#E21 #C3:21 Reserve - - -
#E22 #C3:22 Power parking brake switch illumination and ashtray lighting Ulow Ubat -
#E23 #C3:23 Alarm diode, power supply Alarm activated: 5 V 0.5Hz 5% duty
Alarm triggered: 5 V 4Hz 25% duty
-
#E24 #C3:24 Reserve - - -
#E25 #C3:25 Reserve - - -
#E26 #C3:26 Reserve - - -
#E27 #C3:27 Reserve - - -
#E28 #C3:28 Reserve - - -
#E29 #C3:29 Reserve - - -
#E30 #C3:30 Reserve - - -
#E31 #C3:31 Reserve - - -
#E32 #C3:32 Switch, trunk lid/tailgate private locking Ulow Ubat /Ulow -
#E33 #C3:33 Reserve - - -
#E34 #C3:34 Reserve - - -
#E35 #C3:35 Start button, input signal - - -
#E36 #C3:36 Reserve - - -
#E37 #C3:37 Courtesy lamp Ubat /Ulow Ubat /Ulow -
#E38 #C3:38 Reserve - - -
#E39 #C3:39 Positive temperature coefficient (PTC) heater, control signal Ulow Ubat -Ulow /Ulow -
#E40 #C3:40 Reserve - - -
#E41 #C3:41 Hazard warning flasher switch illumination Ubat -U low if activated; Ulow otherwise -
#E42 #C3:42 Reserve - - -
#E43 #C3:43 Reverse lockout, power supply - - -
#E44 #C3:44 Twilight sensor Ulow U = 0.25-4.75 V -
#E45 #C3:45 Reserve - - -
#E46 #C3:46 Reserve - - -
#E47 #C3:47 Communication CAN_H high speed network During communication the voltage is 2.0-3.5 V -
#E48 #C3:48 Communication CAN_L high speed network During communication the voltage is 1.5-2.5 V -
#E49 #C3:49 Communication LIN bus 3 During communication the voltage is 0 V - Ubat Steering column lock module (SCL)
#E50 #C3:50 Communication LIN bus 3 During communication the voltage is 0 V - Ubat Start control module (SCU)
#E51 #C3:51 Communication LIN bus 1 During communication the voltage is 0 V - Ubat Steering wheel module (SWM)
#E52 #C3:52 Communication LIN bus 1 During communication the voltage is 0 V - Ubat Light switch module (LSM)
#E53 #C3:53 Reserve - - -
#E54 #C3:54 Reserve - - -
#E55 #C3:55 Forward sensing module (FSM), power supply Ulow Ubat -
#E56 #C3:56 Reserve - - -
#E57 #C3:57 Reserve - - -
#E58 #C3:58 Reserve - - -
#E59 #C3:59 Reserve - - -
#E60 #C3:60 Reserve - - -
#F1 #C3:61 Reserve - - -
#F2 #C3:62 Reserve - - -
#F3 #C3:63 Reserve - - -
#F4 #C3:64 30-feed, infotainment control module (ICM) and integrated audio module (IAM) Ubat Ubat -
#F5 #C3:65 Reserve - - -
#F6 #C3:66 15-feed, supplemental restraint system module (SRS) and OWS Ulow Ubat -
#F7 #C3:67 Vanity mirror lighting, power supply Ulow Ubat /Ulow Voltage supply alcolock (option)
#F8 #C3:68 15-feed, PTC heater and heated rear seat switch Ubat at ignition in position II; Ulow otherwise -
#F9 #C3:69 Driver information module (DIM), power supply Ulow Ubat -
#F10 #C3:70 Steering wheel module (SWM), power supply Ulow Ubat -
#F11 #C3:71 Steering column lock module (SCL), control signal from driver information module (DIM) Ulow Ubat /Ulow Does not apply to the USA/CDN markets for 2009-
#F12 #C3:72 - - - -
#F13 #C3:73 30-feed, data link connector and climate control module (CCM) Ubat Ubat -
#F14 #C3:74 Start control unit, (SCU), power supply Ulow Ubat -
#F15 #C3:75 Roof hatch, voltage feed Ubat Ubat -
#F16 #C3:76 Relay, steering column lock module (SCL), power supply - - Does not apply to the USA/CDN markets for 2009-
Fig 4: Identifying 20-Pin Connector
GLL155454Courtesy of VOLVO CARS CORPORATION
Connector C4 (Black)
Breakout box terminal  Control module terminal  Signal type  Ignition off 
Active/Not active 
Ignition on 
Active/Not active 
Miscellaneous 
#B21 #C4:1 Parking brake switch illumination and ashtray lighting. Ulow Ubat -
#B22 #C4:2 Seat belt reminder LED, power supply Ulow Ubat /Ulow -
#B23 #C4:3 Speed roof hatch, control signal Ulow Ubat -Ulow /Ulow -
#B24 #C4:4 LIN bridge During communication the voltage is 0 V - Ubat Vehicles with keyless system
#B25 #C4:5 Communication LIN bus 0 During communication the voltage is 0 V - Ubat -
#B26 #C4:6 High level brake light, power supply Ulow Ubat /Ulow -
#B27 #C4:7 Communication LIN bus 2 During communication the voltage is 0 V - Ubat Movement sensor (IMS)
#B28 #C4:8 Communication LIN bus 2 During communication the voltage is 0 V - Ubat Rain sensor module (RSM)
#B29 #C4:9 Reserve - - -
#B30 #C4:10 Reserve - - -
#B31 #C4:11 Reserve - - -
#B32 #C4:12 Emergency brake light, power supply Ulow Ubat /Ulow -
#B33 #C4:13 Reserve - - -
#B34 #C4:14 Sunroof, global closing Ubat /Ulow Ubat /Ulow -
#B35 #C4:15 Movement sensor (IMS), Power supply Ubat Ubat -
#B36 #C4:16 Remote receiver (RKE/RRX), voltage feed Ubat Ubat Remote Receiver Module (RRX) for keyless system.
Remote receiver Module (RRX) for non-keyless system.
#B37 #C4:17 Rain sensor module (RSM), power supply Ulow Ubat /Ulow -
#B38 #C4:18 15-feed, anti-dazzle rearview mirror Ulow Ubat -
#B39 #C4:19 Reserve - - -
#B40 #C4:20 Interior lighting, roof Ubat /Ulow Ubat /Ulow -