Checking the power supply and ground terminals

Fig 1: Identifying Ignition In Off Position

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off.
• Disconnect the connector to the Engine Control Module (ECM).

  Checking the power supply 

  Check fuses.

  Check the voltage feed to the Engine control module (ECM).

  Take readings between:

  • Engine Control Module (ECM) #B1 (#C1) and system relay.
  • Engine Control Module (ECM) #B3 (#C3) and system relay.
  • Engine Control Module (ECM) #B5 (#C5) and system relay.

  Checking the ground terminal 

  Check the ground terminal and the wiring connected to it. Check for contact resistance and oxidation.

  Take readings between:

  • Engine control module (ECM) #B2 (#C2) and grounding point.
  • Engine control module (ECM) #B4 (#C4) and grounding point.
  • Engine control module (ECM) #B6 (#C6) and grounding point.

  Remedy as necessary.

  Other information 

  • See Connecting the breakout box, engine control module (ECM)
  • See Signal specification, engine control module (ECM)
  • See Checking wiring and terminals
  Fig 2: Identifying Atmospheric Pressure Sensor

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Was a fault detected? 

• YES 

  OKAY:  Troubleshooting has been completed.

• NO 

  Refer to Information