Conditions For Running DTC

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, 2002 Chevrolet RV Cutaway, and 2002 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

4L60-E

Transmission is in D4.
The system voltage is 8-18 volts.

4L80-E

No TPS DTCs P0121, P0122, P0123, P1120, P1220 or P1221.
No VSS DTCs P0502 or P0503.
No incorrect gear ratio DTC P0730.
The engine is running for greater than 60 seconds.
Ignition voltage is 6-18 volts.
The commanded gear is 3rd or 4th.
The throttle angle is 5 percent or greater.
The engine torque is greater than 50 ft. lbs. (68 N.m).
The vehicle speed is 20 MPH or greater.