Bluetooth module available for your 5902, 5903, 5905, 7902, early 7903, 7905, 7907, 7909L, 7909J.
If your unit has a blue 8-pin circular DIN female connector OR a slave 4-pin white power connector and RCA connectors labeled input, there is a great chance you can add this Bluetooth module to it.
 
Specifications:
- Bluetooth 5.0 with aptX-HD codecs.
- 24-bit 192 kHz
- Frequency response: 20 Hz to 20 kHz +-0.5 dB
- Noise level: -96.6 dB(A)
- THD: 0.002 %
- Crosstalk: -90.5 dB
 
Just plug and play. Connect power and audio signal, pair it with your phone and play.
This pause the head unit and fed Bluetooth audio signal.
Pressing Tuner or Disc will pause the Bluetooth stream.
 
No tone or volume control on the head-unit. Volume can still be controlled on the phone.