I was examining Initiation sigs from a scanner to OBD1 in an attemp to make a HH digital tool and used a Tek TDS-3012.
Small Phos color Digital design/de-buger type scope with time frames of 5 Gs/s..
It also has a Single signal capture feature for each trigger ..so I was able to get each pulse time and amplitude sq. wave configeration, but i was not able to break the coding sequence they use...

I have access , if need be..