2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1831
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-volt 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 volt at rest to approximately 4 volts when fully
depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 volt at rest to approximately 2 volts 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 8 volts.
* The DTCs run continuously once the above conditions are met for greater than 200 ms.
Conditions for Setting the DTC
P2122
* The APP sensor 1 voltage is less than 0.74 volt and APP sensor 2 voltage is less than 0.62 V for greater than 1 s or for a cumulative time of 4
s.
OR
* The APP sensor 1 voltage is less than 0.74 volt for greater than 1 s or for a cumulative time of 4 s.
P2123
The APP sensor 1 voltage is greater than 4.82 volts for greater than 1 s or for a cumulative time of 4 s.
P2127
The APP sensor 2 voltage is less than 0.63 volt for greater than 1 s or for a cumulative time of 4 s.
P2128
The APP sensor 2 voltage is greater than 4.82 volts for greater than 1 s or for a cumulative time of 4 s.
P2138
* The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 0.25 volts when the sensor voltages are between
1.91-1.25 V.
* The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 0.31 volts when the sensor voltages are between
1.91-2.63 V.
* The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 1.7 volts when the sensor voltages are greater than
2.63 V.
* DTC P2138 sets if any of the above conditions exist for greater than 1 s or for a cumulative time of 4 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-volt reference circuits if you suspect high resistance in the circuit. The current output should be greater than 80 mA
