VOLVO
RDAR-0009 - Battery voltage. Faulty signal
System
Unknown System / Manufacturer Specific
Volvo models this fault code applies to
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 radio receiver (RDAR) compares its supply voltage with the reading from the central electronic module (CEM) and has registered a deviation. The fault can come from contact resistance or a damaged supply cable, and then the digital radio does not work.
Possible causes
- Contact resistance in the supply
- Damaged supply cable
What you can do
- 1Check that the fuse for the digital radio is not blown or half burned by temporarily fitting a new fuse
- 2With a multimeter, check that the supply voltage reaches the receiver. If it is missing, check the connectors and the cable for breaks and poor contact
- 3Check that the battery is in good condition and that its terminals are tight
- 4Clear the code and road test the car. If it returns, have a workshop carry on with the fault-tracing
Symptoms you may notice1
- The digital radio does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.