VOLVO
PHM-0018 - Carphone box power supply. Signal too low. Intermittent fault
System
Phone Module (PHM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS80 (1999–2006), V70 (2000–2008)
Show models by year and engine (2)
What does this fault code mean?
Although the code is named signal too low for the carphone box power supply, it applies to the power supply being short-circuited to ground. The fault is intermittent, so it may come and go. While it is present, the telephone does not work.
Possible causes
- The power supply to the carphone box is short-circuited to ground
What you can do
- 1Check that the connectors to the carphone box are secure and free from corrosion
- 2Read and note the code, clear it and road test the car to see whether it returns
- 3If it returns, have a workshop with diagnostic equipment check the power supply wire to the carphone box for a short to ground
Symptoms you may notice1
- The carphone does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.