Checking the power supply and ground for the engine control module (ECM)

Checking the power supply 

• Check the fuse for the engine control module (ECM) in the fusebox in the engine compartment. See approbate Wiring diagram Service Manual. If the fuse is blown, check the circuit after the fuse. Check for a short-circuit to ground
• Check the power supply to the engine control module (ECM). The voltage must be approximately battery voltage.

Checking the ground terminal 

• Check the ground leads between the engine control module (ECM) and the ground terminal. Check for an open-circuit
• Check the ground terminal for the engine control module (ECM). Check for contact resistance and oxidation.

Remedy as necessary

Other information 

• To connect the breakout box, see Connecting the breakout box
• For information about the location of ground terminal for B52X4 S/S2, see Location of components . For information about the location of ground terminal for B52X4T see Location of components . For information about the location of ground terminal for B6304S see Location of components . For information about the location of ground terminal for B6284T see Location of components . For D5252T see Location of components
• For information about signals, see ELECTRICAL SYSTEM

Fig 1: Identifying Breakout Box

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Identifying Voltage Display

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 3: Identifying Engine Control Module

Courtesy of VOLVO CARS OF NORTH AMERICA.

Was a fault detected? 

• YES 

  Refer to Checking the engine control module (ECM) 

• NO 

  Refer to Checking communication with the engine control module (ECM)