VOLVO
PHM-0020 - Handset microphone. Signal too high / Signal missing
System
Phone Module (PHM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
Applies to the following models:
5 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013), XC90 (2003–)
What does this fault code mean?
The handset microphone gives either a signal that is too high or no signal at all. The causes are an open circuit in the wire between the handset and the control module, or poor contact in the connectors. The handset does not work, but hands-free still operates.
Possible causes
- Open circuit in the microphone wire running from the handset to the control module
- Poor contact, oxidation or a loose joint in the connectors
What you can do
- 1Check that the handset connector is firmly seated and free from oxidation
- 2If the connectors are in order, use a multimeter to check that the microphone signal wire has no open circuit
- 3If no fault is found in the wire, have a workshop try replacing the handset or the holder
Symptoms you may notice2
- The carphone handset does not work
- Text message in the display, only where the phone module (PHM) runs Volvo On Call
What the fault can affect1
- Only hands-free operates
General guidance for car owners. Diagnosis on the car can point to a different cause.