I took my car in for an air conditioning problem and the technician said he'd plug in the OBDII reader, and I said its a '95 its OBDI, and he showed me the plug, plugged in the reader and told me my in-dash temp sensor was the problem. He said that for the '95 model year Porsche was required to make 20% of their cars OBDII. Has anyone ever heard this before?

 

No but the PSTII can kick down to OBD1 and function like the bosch hammer (9288).

 

Maybe this is a misunderstanding and related to the physical interface/connector. The 993's are all the same with respect to implemented protocols and electrical connections. Early 993's and 964 have a round 19-pin connector and not the more modern OBD2-style connector. These round connectors are often called OBD1, and were the closest Porsche could come to a OBD specification at those early stages. The circuitry and software interface in the car is essentially the same.

OBD1 and OBD2 specifications aren't all that different, and most cars with OBD1 have functionality and protocols implemented that really belong to the OBD2 specification.

By the way, thechief, I'll bet your inboard temp sensor is simply dirty, it can easily be cleaned: CCU repair page
Regards,
Tore

 

What is your symptom? My AC is weak...hoping for a miracle cure not involving AC recharge, but perhaps a CCU fan fix... It's squeaky anyways and I'm looking for a reason to get in there...

 

my symptom, and this is more pronounced on hot days, turn A/C on and over time it gets less cold, the pressures are all good, OBD error code says dash sensor is inop. Are you having similar problem?

 

Easy fix thechief! And a very common problem. Dirty sensor inside the air duct in the CCU.
Have a look here: My CCU repair page

 

Thanks ToreB, I did not know this, since the OBDII code reader plugged in and gave a readout of all the error codes, that led me to believe my car is OBDII, which didn't make sense to me at all, and because the technician said all the OBDI cars used the round plug.

 

My car is a very late build '95 (July '95) I have an OBD2 connector, but an OBD1 car. I suspect yours is the same.
My advice is to find a Porsche specialist that knows something about 993s.