939003718 - N025 SUBWOOFER NOT WORKING

all the audio channels operate correctly except the subwoofer
1CHECK CORRECT POWER SUPPLY TO WOOFERALL OKPROBLEMS ENCOUNTEREDACTION
Check the subwoofer power supply is correct by carrying outSee Test 5570TC CHECK ON OPERATION OF SUBWOOFERMove on to Step 2Power supply interruptedRestore correct power supply, see wiring diagram    See E3510 RADIO
2CHECK THE AUDIO SIGNALS CONTROLLING THE SUBWOOFERALL OKPROBLEMS ENCOUNTEREDACTION
Check for the presence of audio signals controlling the subwoofer by carrying outSee Test 5570TC Move on to Step 3Audio signals interruptedRestore the correct audio signal wiring
3CHECK SUBWOOFER ACTIVATION ENABLEMENT SIGNALALL OKPROBLEMS ENCOUNTEREDACTION
Check that a subwoofer activation enablement signal is present by carrying outSee Test 5570TC Move on to Step 41. Subwoofer activation signal interrupted.1. Restore the correct signal.
2. Subwoofer defective2. Replace Bose subwoofer    Op. 5580T40 BOSE SOUND SYSTEM SUBWOOFER - R.R.
3. Audio amplifier defective.3. Replace Bose audio amplifier    Op. 5580T42 BOSE SOUND SYSTEM AMPLIFIER - R.R.
4CHECK ON CORRECT OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
Check that the fault is no longer presentEnd of diagnosis