2010 Cadillac CTS Sedan AWD V6-3.6L Page 1039
Circuit/System Description
The throttle body assembly contains 2 throttle position sensors. The TP sensors are mounted to the throttle body assembly and are not serviceable.
The TP sensors provide a signal voltage that changes relative to throttle blade angle. The Engine Control Module (ECM) supplies the TP sensors
with a common 5 V reference circuit , a common low reference circuit, and two independent signal circuits. The TP sensors have opposite
functionality. TP sensor 1 signal voltage decreases from greater than 4 V at idle to less than 1 V at wide open throttle (WOT). TP sensor 2 signal
voltage increases from less than 1 V at idle to greater than 4 V at WOT.
Conditions for Running the DTC
* The ignition voltage is greater than 7 V.
* The ignition is ON, with the engine OFF, or the engine is operating.
* DTC P0121 runs continuously once the above conditions are met.
Conditions for Setting the DTC
P0121
The TP sensor 1 disagrees greater than 9 percent from TP sensor 2, or TP sensor 1 disagrees greater than 9 percent from the predicted value for
greater than 1 s.
P0122
The ECM detects the TP sensor 1 signal voltage is less than 0.18 V for greater than 1 s.
P0123
The ECM detects the TP sensor 1 signal voltage is greater than 4.6 V for greater than 1 s.
P0221
The TP sensor 2 disagrees greater than 9 percent from TP sensor 1, or TP sensor 2 disagrees greater than 9 percent from the predicted value for
greater than 1 s.
P0222
The ECM detects the TP sensor 2 signal voltage is less than 0.16 V for greater than 1 s.
P0223
The ECM detects the TP sensor 2 signal voltage is greater than 4.9 V for greater than 1 s.
Action Taken When the DTC Sets
* DTCs P0121 and P0221 are Type B DTCs.
* DTCs P0122, P0123, P0222, and P0223 are Type A DTCs.
Conditions for Clearing the DTC
* DTCs P0121 and P0221 are Type B DTCs.
* DTCs P0122, P0123, P0222, and P0223 are Type A DTCs.
Diagnostic Aids
If there is a condition with the TP sensors the ECM defaults to reduced power mode for the entire ignition cycle, even if the condition is corrected.
