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 Ohm Meter

Courtesy of VOLVO CARS CORPORATION

Fig 3: Identifying Relays And Terminals

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Refer to INFORMATION