Checking the Carphone Handset

Checking the carphone handset

Checking components and wiring
In case of open circuit/short-circuiting of cables, defective handset or connector, the carphone handset will not work. This results in the user only being able to use handsfree.

Checking connectors and cables
Check the cable for voltage feed between phone module (PHM) connector #A7 (#7) and the handset's connector #5 (#25) for open circuit.
Check the cable for ground between phone module (PHM) connector #A18 (#18) and the handset's connector #3 (#23) for open circuit, short-circuit to ground and short-circuit to voltage.
Check the connectors for loose connections, damaged or bent pins as well as oxidation.
If no malfunction was found, try replacing the handset.

Other information:
- For further information about the fuses and relays, see wiring diagram.
- Connecting the breakout box Connecting the Breakout Box, Phone Module (PHM)
- Signal specification Signal Specification, Phone Module (PHM)
- Location of components Locations
- Phone module (PHM), replacing Phone Module (PHM), Replacing
- Handset, replacing Handset, Replacing
- Checking wiring and terminals Checking Wiring and Terminals





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