Condition 3

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The TP angle is 10-50 percent.
The PCM commands fourth gear.
The TCC is locked ON.
The speed ratio is 0.6-0.75, speed ratio is engine speed divided by transmission output speed.
The PCM detects a gear range of PARK or NEUTRAL when the vehicle is operating in D4.
All conditions met for 10 seconds.