Full System Code Reader?

I use an Edge Insight CTS - Displays and clears Diagnostic Trouble Codes.

To the best of my knowledge Chevy Express vans only seem to be popular with the trades groups these days and van forums with any decent information are virtually non-existent. I'll poke around the Chevy pickup sites though since the equipment should be similar.

It really does depend on the specific vehicle. Using my Sprinter chassis as an example, there are "zillions" of codes from every computer in the vehicle that can be accessed via the OBD port, but Mercedes has done an effective job of keeping the chassis-specific codes a secret. There are only a few several thousand $ devices that can read the proprietary codes. You'd probably have better luck on a forum dedicated to the chassis type, rather than an RV forum.

donn0128 wrote:
That is because your plugging into the ODB port which is only reading the ECM (engine control module). To read other codes you need to read the BCM.

It depends on the vehicle, and I suspect the code reader as to which codes you can read through the OBDII port. On at least one of my vehicles, I can read many non ECM codes through the OBDII port. Scanguage is one such device that in addition to giving mileage etc. readouts will also alert you to many pending codes as well as any "thrown" codes. Scanguage will also let you clear many codes as well.

However, resetting (clearing) the codes is also not always possible through the OBDport. On one of my vehicles, the airbag is one such code that can't be reset through the OBDII port, but needs another device or SW to reset.

However, go to your local auto store, often they can at least read out the code for you.

That is because your plugging into the ODB port which is only reading the ECM (engine control module). To read other codes you need to read the BCM.