Conditions for Running the DTC

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The engine is running.
The vehicle speed is 0 km/h (0 mph).
The ignition voltage is between 9-18 volts.
The transfer pump is activated.
A slosh delay of 20 seconds has passed.
DTC P2636 runs continuously when the above conditions are met.