Checking the signal cable

Fig 1: Identifying Ignition OFF

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Identifying Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off
• Engine coolant temperature (ECT) sensor connector disconnected.

  Connect an ohmmeter between engine coolant temperature (ECT) sensor connector terminal #1 (control module side) and ground.

  Fig 3: Identifying Engine Coolant Temperature (ECT) Sensor And Connector Terminals

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  Fig 4: Identifying Ohmmeter

  Courtesy of VOLVO CARS OF NORTH AMERICA.

The ohmmeter must read more than 1000 Ω. 

• OK 

  Refer to Defective engine coolant temperature (ECT) sensor 

• NOT OK 

  Refer to Checking the cable