Yes, and the plug-in standardized OBDC reader socket design, reader communication protocol, and generic emission code numbers were required by regulation in the US after 1996.
Being the world's largest market, car manufacturers moved from whatever proprietary system they were using to the US standard with added proprietary manufacturer-specific non-emission module codes and extended codes related to the engine.
Andy

Where did OBDC come from?

 

Would I be correct in reading 1, 1, 2, 4, as intermittent O2 sensor?

 

Bump
Would I be correct in reading 1, 1, 2, 4, as intermittent O2 sensor?

 

Hi JPS,

Yes, 1224 equals O2 sensor, possible loose/intermittent contact.

 

Thx

 

Would the codes be the same for a 1993 968? The procedure worked and gave me 1131, knock sensor #1. I haven’t found a dealership or shop within 100 miles that has the connector to read it for me.

Thanks for the great info!

 

No. You are in the 993 Forum.

 

OK, found the codes for the 968. Looks like any number that's in both lists has the same meaning, except for the cylinder numbers on injection valve faults. Then each list has a couple that aren't in the other. So my code is reading knock sensor 1.

https://rennlist.com/forums/968-foru...ink-codes.html

Someone had sent me to this thread because it describes the procedure clearly. Thank you for answering my question.

 

I’ve had that and I bet it’s the green connector on top of the engine. Gets heat soaked and wet during washes.
break/make the connector a few times. A squirt of contact cleaner and you should be good for another 25 years

 

Thanks so much! I’ll try that.