DTC will set when the following conditions are present:

WARNING: This page is about a different car, the 1997 GMC Pickup and 1997 Chevrolet Pickup. However, it is still accessible from the selected car via links, so may be relevant.

No TP sensor DTCs are set.
No MAF DTCs are set.
No IC control DTCs are set.
No VSS DTCs are set.
No crankshaft position sensor DTCs are set.
Rough road condition is not detected.
Engine coolant temperature is 20-203°F (-6.75 to 95°C).
Engine speed is 600-5600 RPM.
System voltage is 9-16 volts.
Positive throttle position change is less than 4.9 percent for 100 milliseconds.
Negative throttle position change is less than 2.9 percent for 100 milliseconds.
Misfire is detected.