It plugs right into the OBD2 port in front of the shifter and talks to my Optimus V phone through bluetooth. You don't need the CD, in fact throw it away immediately because it supposedly contains a trojan. Thanks China.
Anyway, the app connected to the ELM327 and I was immediately checking the ECU for stored trouble codes (had none), and getting a bunch of raw signal data off the ECU. The free app is kind of clunky so I bough the $4.95 paid version which is much nicer. On my 96 850 it can display the following signals:
RPM
TPS
MAP (my NA has a map sensor which was news to me)
MAF
O2 sensor 1 voltage (needs to be replaced, very lazy switching rate)
O2 sensor 2 voltage
Air temp
Coolant temp
Transmission temp (I don't trust this one since its a manual)
Ignition timing
Instant MPG (much faster update rate than the Volvo trip computer)
Avg MPG
Speed
Avg speed
Long term fuel trim
Short term fuel trim
Voltage
All done in real time.
In addition it has its own caculated imputs:
Acceleration in 3 separate axis (0-60, 1/4 mile etc)
Calculated engine load
GPS/ECU speedometer error
Cost per mile, per minute, etc
It can datalog all of these parameters and email them to your PC to turn into pretty graphs, charts etc. Newer OBD2 cars have even more outputs that can be accessed. One thing it can't do access the ABS, SRS and ECC modules because it only knows the universal OBD2 codes. But if I can find the PID data for the other volvo specific trouble codes, they can be added and accessed by torque.
All the displays can be customized.


Not bad for a $29 investment. I recommend it for anyone with a 1995+ 850.






