Checking The Power Supply And Ground For The Trailer Module (TRM)

Fig 1: Identifying Ignition OFF

Courtesy of VOLVO CARS CORPORATION

• Ignition off.

  Check that the following fuses are intact:

  • Main fuse by battery
  • Fuse for the trailer module (TRM).

  Check the power supply cable to the trailer module (TRM). Check for a short-circuit to ground. Check for an open-circuit.

  Check the cable between the ground terminal and the trailer module (TRM). Check for an open-circuit. Check for a short-circuit to supply voltage.

  Check the ground terminal for the trailer module (TRM). Check for contact resistance. Check for oxidation.

  Other information 

  • see CHECKING WIRING AND TERMINALS
  Fig 2: Identifying Ohms Display

  Courtesy of VOLVO CARS CORPORATION

Was a fault detected? 

• YES 

  Refer to VERIFICATION 

• NO 

  Refer to CHECKING COMMUNICATION WITH THE TRAILER MODULE (TRM)