According to the manual:
OPERATING RANGE FOR HYBRID
SYSTEM START FUNCTION
The Intelligent Key can only be used for
starting the hybrid system when the
Intelligent Key is within the specified
When the Intelligent Key battery is almost
discharged or strong radio waves are
present near the operating location, the
Intelligent Key system’s operating range
becomes narrower and may not function
I know that the OP thought that wasn't an issue because he was in a Home Depot parking lot, etc, etc. Simple fact of the matter is that radio waves don't always follow logic and this could be a factor.
I had this happen once. Fortunately, I had read the manual, and did put the key next to the start button:
If the battery of the Intelligent Key is
discharged, or environmental conditions
interfere with the Intelligent Key operation,
start the hybrid system according to the
1. Move the shift lever to the P (Park)
2. Firmly apply the foot brake.
3. Touch the ignition switch with the
Intelligent Key as illustrated. (A chime
4. Push the ignition switch while depressing
the brake pedal within 10 seconds
after the chime sounds. The hybrid
system will start.
After step 3 is performed, when the
ignition switch is pushed without depressing
the brake pedal, the ignition switch
position will change to ACC.
Car started right up. Thinking it was the remote battery, I was close to the dealer and headed over. Of course, I couldn't duplicate the issue at the dealer (we even tested the remote's battery, and it was fine), the only logical explanation was something interfered with the signal.
In today's world of everything, everywhere being constantly bombarded by electronic signals, I find that explanation plausible.