Trouble code info needed

[Shannen Durphey]

Programmer wrote:
> 
> Shannen,
> 
> Either the cross counts on the O2 are too low to be considered an active O2
> circuit (degraded or contaminated sensor), or your A/C system is in need of
> a recharge. GM uses the same code 61 for both symptoms.

A/C code on this model.  Needed trouble tree to trace it.  According
to the tree, the PCM measures evaporator temperature, high side
pressure, and vehicle speed to determine refrigerant pressure.  This
also means the code won't set at idle.  I've never run into this
situation before.  The tree was really helpful.
Shannen