OBDII Scanner Kills Engine

[TheArgobus]

My 1995 E-350 7.3L is in the shop getting the transmission rebuilt. They said they lost communication through the scan tool itself multiple times, and when they finally got it working, they entered "test mode in data stream" and it shut down the engine. Twice. Eventually they got it working and could read the codes (that's a whole different issue).


So what's going on there? How can a scan tool shut down the engine? The shop guy said he suspected it might be because it's a '95 with OBDII (the chassis is a 95 E350, but then Girardin made it into a bus in 96--so maybe they retroactively added OBDII?). Or that perhaps the scan tool acted as a ground and killed the engine that way.



Any ideas?


I have one of those cheap OBDII scan tools, and I never got it to work.

[Mekanic]

I thought They went to OBDII in 96. did Ford use that type of plug But different programming on their earlier vehicles?

[TheArgobus]

You are correct about 1996. The bus has an OBDII plug under the driver's seat, which is what they used, but I suppose it could be some proprietary data format going through the cables. I know it didn't work with my cheap reader.