NB Miata - OBD Mode 5

If you thought Mode 4 was simple, Mode 5 is, in some ways, even simpler.  At least a Mode 4 request causes something to happen.  Mode 5 requests only return information, and that information never changes!

Mode 5 is meant to return information that is used for oxygen sensor monitoring.  In the NB, only the following TIDs are supported:

• 00xx - this is the TIDs supported TID.  It must be two bytes, but the second byte can be anything.  The reply tells you that only TIDs 1 and 2 are supported
• 0101 - returns the rich-to-lean threshold voltage for O2 sensor 1
• 0102 - returns the rich-to-lean threshold voltage for O2 sensor 2
• 0201 - returns the lean-to-rich threshold voltage for O2 sensor 1
• 0202 - returns the lean-to-rich threshold voltage for O2 sensor 2

What makes this mode so uninteresting is that all you can do is request the above threshold voltages.  What's more, they are all the same (0.445V) and never change.  Yawn.

Next up, Mode 6.