Conditions for Setting the DTC
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
P2120
The APP sensor 1 voltage is less than 0.46 V or greater than 4.7 V for greater than 0.2 s.
P2122
The ECM detects that the APP sensor 1 voltage is less than 0.46 V for greater than 0.2 s.
P2123
The ECM detects that the APP sensor 1 voltage is greater than 4.75 V for greater than 0.2 s.
P2125
The APP sensor 2 voltage is less than 0.32 V or greater than 2.6 V for greater than 0.2 s.
P2127
The ECM detects that the APP sensor 2 voltage is less than 0.32 V for greater than 0.2 s.
P2128
The ECM detects that the APP sensor 2 voltage is greater than 2.6 V for greater than 0.2 s.
P2138
The voltage difference between APP sensor 1 and APP sensor 2 exceeds a predetermined value for greater than 1 s.