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. 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 control module ground terminal. Check for contact resistance and oxidation.

Remedy as necessary

Other information 

• See Connecting breakout box for Engine Control Module (ECM). See CONNECTING THE BREAKOUT BOX
• See Signal specification for Engine Control Module (ECM). See SIGNAL SPECIFICATION
• see CHECKING THE VOLTAGE / GROUND TERMINAL

Fig 1: Identifying Engine Control Module (ECM)

Courtesy of VOLVO CARS CORPORATION

Was a fault detected? 

• YES 

  Refer to VERIFICATION 

• NO 

  Refer to CHECKING COMMUNICATION WITH THE ENGINE CONTROL MODULE (ECM)