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Home >> Volvo >> 2009 >> XC70 Base >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Electrical Modules And Components - Design And Function - 5 Of 5 >> Trailer Module (TRM) >> System Overview >> Signals
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System Overview: Signals

The table below summarizes the input signals to and output signals from the trailer module (TRM). The signal types are divided into directly connected signals and CAN communication. Fig 1 displays the same information with the Volvo component designations.

Input signals Output signals
Directly connected:  Directly connected: 
  • Stop lamp signal from Central electronic module (CEM) (4/56) via left tail lamp.
  • To tow hitch cable harness:
    • Right turn signal lamp
    • Left turn signal lamp
    • Stop lamp right
    • Stop lamp left
    • Parking lamps
    • Back-up lamp
    • Fog lamps
    • Charging (+12 V voltage).
Via Controller Area Network (CAN) communication:  Via Controller Area Network (CAN) communication: 
  • Central electronic module (CEM) (4/56)
  • Central electronic module (CEM) (4/56)
  • Driver information module (DIM) (5/1)
  • Differential electronic module (DEM) (4/82) (option)
  • Parking Assistance Module (PAM) (4/86) (option)
  • Parking Assistance Camera (PAC) (4/120) (option)
Fig 1: Identifying Input Signals And Output Signals From Trailer Module (TRM)
GLL160603Courtesy of VOLVO CARS CORPORATION