Checking Fuses And Power Supply

Check whether the carphone fuse in the passenger compartment fusebox is half burned by trying a new fuse.

HINT: A half burned fuse can cause intermittent faults. 

Check the power supply to the phone module (PHM) by:

• measuring the voltage between phone module (PHM) connector A terminals #1 (#1) and A #2 (#2)
• measure the battery voltage.

The fault is in the power supply cable if the difference between the power supply for the phone module (PHM) and battery voltage is greater than 2.5 V.

There may be an internal fault in the phone module (PHM) if the difference is less than 2.5 V.

Remedy as necessary.

Other information: 

• To connect the breakout box, see CONNECTING THE BREAKOUT BOX
• For information about signals and connectors, see SIGNAL SPECIFICATION
• To access or replace the phone module (PHM), see PHONE MODULE (PHM), REPLACING
• see CONTENTS .

Fig 2: Breakout Box

Courtesy of VOLVO CARS CORPORATION

Fig 3: Identifying Voltage Display

Courtesy of VOLVO CARS CORPORATION

Refer to VERIFICATION