| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. | 
Circuit  | Short to Ground  | Open  | Short to Voltage  | Signal Performance  | 
|---|---|---|---|---|
TP Sensor 2 Signal  | P0222  | P0223  | P0223  | P0221  | 
TP Sensor 5-Volt Reference  | P0222  | P0222  | P0223  | --  | 
TP Sensor Low Reference  | --  | P0223  | --  | --  | 
Circuit  | Short to Ground  | Open  | Short to Voltage  | 
|---|---|---|---|
Parameter Normal Range: 0.16-4.88 V  | |||
TP Sensor 2 Signal  | 0 V  | 5 V  | 5 V  | 
TP Sensor 5-Volt Reference  | 0 V  | 0 V  | 5 V  | 
TP Sensor Low Reference  | --  | 5 V  | --  | 
The throttle body assembly contains 2 throttle position (TP) 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-volt reference circuit, a common low reference circuit, and 2 independent signal circuits.
The TP sensors have opposite functionality. TP sensor 1 signal voltage decreases from above 4 volts at idle to below 1 volt at wide open throttle (WOT). TP sensor 2 signal voltage increases from below 1 volt at idle to above 4 volts at wide open throttle.
The ECM compares the signal of the TP sensor 1 and TP sensor 2 through the entire operating range.
| • | The system voltage is more than 7 volts. | 
| • | The TP sensor 2 voltage is between 0.16-4.88 volts. | 
| • | DTCs P0221, P0222, and P0223 run continuously when the above conditions are met. | 
| • | The TP sensor 1 disagrees more than 6.3 percent from TP sensor 2 for over 140 ms. | 
| • | The TP sensor 2 disagrees more than 9 percent from the throttle position calculated from mass air flow (MAF) signal for over 280 ms. | 
The TP sensor 2 voltage is less than 0.16 volt for over 140 ms.
The TP sensor 2 voltage is more than 4.88 volts for over 140 ms.
| • | DTC P0221 is a Type B DTC. | 
| • | DTCs P0222 and P0223 are Type A DTCs. | 
| • | The control module commands the TAC system to operate in the Reduced Engine Power mode. | 
| • | A message center or an indicator displays Reduced Engine Power. | 
| • | DTC P0221 is a Type B DTC. | 
| • | DTCs P0222 and P0223 are Type A DTCs. | 
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
| ⇒ | If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. | 
| ⇒ | If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. | 
| ⇒ | If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. | 
| ⇒ | If less than 4.8 volts, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the ECM. | 
| ⇒ | If greater than 0.1 volt, test the TP sensor 2 signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. | 
| • | ECM X1 5-volt reference circuit terminal 39 to terminal E. | 
| • | ECM X1 signal circuit terminal 89 to terminal F. | 
| ⇒ | If greater than 5 ohms, repair the affected circuit. | 
| ⇒ | If less than infinite resistance, repair the short between TP sensor 1 signal circuit and TP sensor 2 signal circuit. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |