2010 Cadillac CTS Sedan AWD V6-3.6L Page 1857
Circuit/System Description
The accelerator pedal assembly contains two accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are
not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module
(ECM) supplies a separate 5 V reference and low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1.0 V at rest to approximately 4 V when fully depressed.
The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 V at rest to approximately 2 V with the accelerator
pedal fully depressed.
Conditions for Running the DTCs
* The ignition is ON or the engine is operating.
* The ignition voltage is greater than 7 V.
* The DTCs run continuously once the above conditions are met.
Conditions for Setting the DTC
P2122
The APP sensor 1 voltage is less than 0.74 V for greater than 1 s.
P2123
The APP sensor 1 voltage is greater than 4.82 V for greater than 1 s.
P2127
The APP sensor 2 voltage is less than 0.63 V for greater than 1 s.
P2128
The APP sensor 2 voltage is greater than 4.82 V for greater than 1 s.
P2138
* The ECM detects that the voltage difference between APP sensor 1 and the calculated idle range is greater than 0.25 V, with a released pedal.
* The ECM detects that the voltage difference between APP sensor 2 and the calculated idle range is greater than 0.31 V, with a released pedal.
* The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 0.31 V with a partially pressed pedal.
* The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 1.70 V with a fully pressed pedal.
* The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 0.04 V when APP sensor 1 is greater than 1.17 V.
* Any of the above conditions exist for greater than 1 second, or a cumulative of 10 s.
Action Taken When the DTC Sets
DTCs P2122, P2123, P2127, P2128, and P2138 are Type A DTCs.
Conditions for Clearing the DTC
DTCs P2122, P2123, P2127, P2128, and P2138 are Type A DTCs.
Diagnostic Aids
Test the current output of the 5 V reference circuits if you suspect high resistance in the circuit. The current output should be greater than 80 mA
for APP 1 and greater than 50 mA for APP 2.
