Conditions for Running the DTC: Notes

WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The engine speed is greater than 450 RPM.

P1684

No DTCs P0711, P0712, P0713, P0716, P0717, P0722, P0723, or P1684.
DTC P1684 has not passed this key ON.
The TCM power up temperature is between -39 and +149°C (-38 and +300°F).

P1685

No DTCs P0716, P0717, P0722, or P0723.
The transmission output shaft speed is greater than 200 RPM for greater than 200 seconds.
The torque converter clutch (TCC) slip speed is equal to or greater than 120 RPM for 200 seconds or greater.
DTC P1685 has not failed this ignition cycle.