Diagnostic trouble code (DTC) informationREM-7A20

Condition 

The Rear electronic module (REM) checks the voltage supply to the Subwoofer module (SUB) via a driver stage.

The diagnostic trouble code (DTC) is stored if the control module detects that the output has a short-circuit to supply voltage or if the driver stage has a too high a temperature.

The diagnostic trouble code (DTC) can be diagnosed in ignition positions I or II.

Fig 1: Identifying Rear Electronic Module (REM)

Courtesy of VOLVO CARS OF NORTH AMERICA.

Substitute Value 

• The control module deactivates the output.
• If the fault has been detected in 100 ignition cycles, the output is closed permanently until the diagnostic trouble code is erased (applies from structure week 200539).

Possible Source 

• Short-circuit to supply voltage in the signal cable.
• Internal fault in Rear electronic module (REM).

Fault symptom[s] 

• Subwoofer sound reproduction. Doesn't correspond to set position.
• No sound from subwoofer