OBDII works and doesn't

Have you had any complaints about some values working then not? I’ve been having a terrible time reading some items consistently. Currently the oil pressure is not working. It was, but not now. Sometimes if I delete the item and re-add it, it works again. I’m also not getting oil temperature to work. These all work when I use HPTuners wtth their MPVI2. If this is a CAN vs. OBDII issue then why is the oil temp selectable in the ECU list using OBDII? The other issue is with logging. Currently I’m getting the RPM to display. But the RPM will not log. Other values are being logged to the file.

All inputs are listed as selectable inputs regardless of the connection type. Especially with OBD2, there is no way of knowing beforehand what values will be received, so it makes no sense trying to hide any of the input values.

If you have an option to use direct CAN connection, I would never even consider using OBD2, as it is slow and cumbersome compared to CAN.

For logging the values, check the ‘Settings->Application->Data Logging’ and ‘Select Values’ button if RPM is listed as datalogged value.

Thanks. That makes perfect sense. But in the case of the oil pressure, it did work. It just doesn’t right now. Next time I’m working on the car I’ll delete and re-add it to see if it works again.

As far as CAN goes, I’ve had a terrible time trying to make it work. In fact, even some of the OBDII readers don’t work. I have 3 OBD adapters; ELM 327, BAFX and OBDLink+. Only the BAFX works. I had email conversations with OBDLink tech support recently and they couldn’t help. I have the USB-CAN analyzer but couldn’t get that to work either.

I don’t expect you can help, or any others reading this, but the ECU is an GM 2012 E39 ECU with a tune from HPTuners. (HPTuners works using their proprietary adapter) There is something unique with this GM ECU protocol and there doesn’t seem to be many people using it.

We have read dozens of GM E39 ecus with CAN adapter (not OBD2), so it should definitely be possible unless special tune has somehow disabled the CAN output, which is not likely.

Just dig out the CAN H and CAN L pins on your OBD2 port, stick the CAN adapter to those pins and USB to RealDash device. You should be seeing some data flow in CAN Monitor.