Idle airflow

I watched webinar 217 and attempted to follow. I set up the idle airflow graph as directed and copy and pasted coolant temps from the from the target idle speed vs. coolant temp table. It started at -40*f and went 300*f. I began the cold start scan, yet the values only populated the -40 cell in the histogram, no other cells would populate even as the engine began to warm. Any thoughts? Everything is in Fahrenheit. I figured info would populate throughout the histogram.

Notes. 2009 Silverado 5.3. BTR stage two cam recently installed. Tuned on a dyno by a pro. Seems to run ok. Gets 11 mpg now. Uhg. Tuner says all is fine. I’m fascinated about tuning and want to learn. I’m taking your classes. This is my first attempt to actually making a change.

Bit of a long shot, but ...

I don't know about your specific vehicle, but sometimes there are two temperature senders - one for the temperature gauge, and one for the ECU. If it's the case here, you may have a faulty ECU temp sender', or have it unplugged or wiring damage? Does the ECU show a change in temperature?

Thx Gord. I added the coolant temperature sensor channels to see the reading….and it all worked. The histogram filled perfectly. I’m concluding I needed that PID in the channel list for it to work appropriately. Thx for replying and giving me the clue that resolved my issue.

tim