Diagnostic trouble code (DTC) status ECM-8400 5 volt power supply. Signal too low

Reading off Diagnostic trouble code (DTC) status ECM-8400 

• NOTE:

  When reading off the Diagnostic trouble code (DTC) status, other stored diagnostic trouble codes (DTCs) and their status will be listed.

• Read off the Diagnostic trouble code (DTC) status. Check the status of the relevant Diagnostic Trouble Code (DTC).

Fig 1: Identifying VCT2000

Courtesy of VOLVO CARS OF NORTH AMERICA.

Was the status of the relevant Diagnostic Trouble Code (DTC) displayed as permanent? 

• YES 

  Refer to Checking cables 

• NO 

  Refer to Signal too low. Intermittent fault