Checking Components And Wiring

Check the throttle unit and engine control module (ECM) connectors. Check for contact resistance and oxidation.

Check the resistance values of the potentiometers in the throttle unit.

Check that the shutter in the throttle unit is not blocked or sticking. Clean as necessary.

Check the function of the integrated return spring in the throttle unit by carefully manually turning the throttle to wide open position and then carefully releasing the throttle. Check that the return spring returns the shutter to its resting position.

If the return spring does not return the shutter, the throttle unit is defective.

Remedy as necessary.

Other information: 

• See Contents
• For resistance values, see Component specifications
• For information about signals, see ELECTRICAL SYSTEM
• To access or replace the throttle unit, see Throttle body (electronic throttle module (ETM)), replacing
• To clean the throttle unit, see Throttle body (TB), cleaning

Fig 2: Identifying Throttle Unit Connector Terminals (Wiring Side)

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 3: Identifying Ohm Meter

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 4: Identifying Throttle Unit Connector Terminals

Courtesy of VOLVO CARS OF NORTH AMERICA.

Refer to Adaptation of the throttle unit