Checking Voltage/Ground Terminal, Phone Module (PHM)

Checking the supply voltage/ground terminal

Power supply, phone module (PHM)
The phone module (PHM) is powered via a power input on the control module.
Power input terminal #A:5 (#5) is +30-supplied via a fuse from the battery. It will not be possible to activate the control module if there is an open-circuit.

Checking the power supply
Check the power supply cable from the battery to phone module (PHM) terminal #A:5 (#5). Check for an open-circuit. Check for loose connections, contact resistance and oxidation. Check the fuse. The voltage must be battery voltage.

Ground terminal, phone module (PHM)
The phone module (PHM) has a ground input. The ground input from the unit is power ground and is connected to the ground terminal in the car body. See the relevant wiring diagram for further information about the ground terminal.

Checking the ground terminal
Check the ground cable between phone module (PHM) terminal #A:6 (#6) and the ground terminal. Check for open-circuit, loose connections, contact resistance and oxidation. With the ignition on, the drop in voltage between the ground connection for the control module and the ground terminal must not be greater than 0.5 V.
Remedy as necessary.

Other information
- Signal specification Signal Description, Phone Module (PHM)
- Location of components Location Of Components, Phone Module (PHM)
- See the relevant wiring diagram for information about circuit and ground terminals in the bodywork
- Checking wiring and terminals Checking Wiring And Terminals

Continue - DONE

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