VOLVO
AUM-4001 - Antenna amplifier 1. Signal too low. Intermittent fault
System
Audio Unit Module (AUM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007)
Show models by year and engine (4)
What does this fault code mean?
The audio unit (AUM) has detected a low voltage on the output of the main antenna while the ignition is on and the antenna is powered. The fault is intermittent. It is usually a supply wire to the main antenna shorted to ground, or a defective antenna amplifier, and AM reception becomes poor.
Possible causes
- Supply from the head unit to the main antenna shorted to ground
- Defective antenna amplifier
What you can do
- 1Check the contact resistance, oxidation and wiring to the antenna amplifier
- 2Have a workshop clean and secure the connectors at the antenna amplifier and the audio unit
- 3Repair the wiring if it is shorted to ground
- 4Replace the antenna amplifier if the fault remains once the connectors and wiring are checked
Symptoms you may notice1
- Poor AM radio reception
General guidance for car owners. Diagnosis on the car can point to a different cause.