Checking the control module for open-circuits

Check the driver circuit for the relay coil for an intermittent open-circuit as follows:

Activate the relay driver by measuring the voltage between terminals #1 and #2 on the relay base. For further information about intermittent open-circuits.

HINT: The voltage between terminals #1 and #2 should be battery voltage. 

If the value deviates excessively, check the voltage between terminal #2 and the battery and between terminal #1 and ground. Both should equal battery voltage. Check for an intermittent open-circuit. Also check the signal loop between relay terminal #2 (2/17) and central electronic module (CEM) terminal #19A. Check for an open-circuit.

Other information: 

• See Checking wiring and terminals

Fig 2: Identifying Ohmmeter

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 3: Identifying Relays And Terminals

Courtesy of VOLVO CARS OF NORTH AMERICA.

Refer to Information