Does My BMW Have a 20-Pin Diagnostic Port? How to Check in 30 Seconds
Share
Older BMWs have a round 20-pin diagnostic port under the hood instead of (or as well as) the 16-pin OBD2 port under the dash. If yours has one, you'll need an adapter to connect a modern scanner like PASOFT. Here's how to tell in about 30 seconds.
Step 1: Open the hood and look at the driver's side strut tower
The 20-pin port is a round, screw-cap connector, usually grey or black, on or near the top of the driver's side strut tower (the raised mount where the front suspension meets the body). On some models it sits in the engine bay next to the strut tower or on the fender.
- Round cap with a ring of pins underneath: that's the 20-pin port.
- Nothing there: your car uses the 16-pin OBD2 port under the dash, on the driver's side near your knees.
Step 2: Match it to your model
| Model | Chassis | Diagnostic port |
|---|---|---|
| 3 Series / Z3 | E36 | 20-pin under the hood |
| 5 Series | E34 | 20-pin under the hood |
| 5 Series (earlier cars) | E39 | 20-pin under the hood |
| 7 Series (earlier cars) | E38 | 20-pin under the hood |
| 5 Series and 7 Series (later cars) | E39, E38 | 16-pin OBD2 under the dash |
| 3 Series | E46 | 16-pin OBD2 under the dash |
| X5, X3, Z4 | E53, E83, E85 | 16-pin OBD2 under the dash |
Model years overlap during the switch, so always check the car itself rather than relying on the year alone.
"My E36 has an OBD2 port too. Can I use that?"
Many 1996 and later E36 and Z3 cars have both. The OBD2 port under the dash only gives access to basic engine and emissions data. For full access to all the modules (airbags, ABS, instrument cluster and so on), connect through the 20-pin port under the hood.
What you need to connect
- Car with the 20-pin port: the Kit + 20-Pin Adapter Bundle, or the 20-pin adapter if you already own the PASOFT interface.
- Car with only the 16-pin OBD2 port: the PASOFT Scanner Kit plugs straight in.
How to connect through the 20-pin port
- With the ignition off, unscrew the cap on the 20-pin port.
- Push the adapter's 20-pin plug in and turn its collar to lock it.
- Plug the PASOFT interface into the 16-pin end of the adapter, then into your laptop.
- Turn the ignition ON and open PASOFT.
- When you're done, put the cap back on. It keeps water and dirt out of the pins.
A note on older chassis: PASOFT works on the E36 / Z3 and earlier E38 / E39, and on the E34 with limited functions. The adapter also fits the E31 and E32, but PASOFT doesn't support those cars.
Get set up
The PASOFT Scanner Kit includes the USB interface, cable and PASOFT software, with free remote setup support. If your car has the round 20-pin port under the hood, get the Kit + 20-Pin Adapter Bundle instead. Questions about your car? Email info@bmwpasoft.com with your model and year.