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P0122



DTC P0122

DTC DESCRIPTOR

DTC P0120
Throttle Position (TP) Sensor 1 Circuit

DTC P0122
Throttle Position (TP) Sensor 1 Circuit Low Voltage

DTC P0123
Throttle Position (TP) Sensor 1 Circuit High Voltage

DTC P0220
Throttle Position (TP) Sensor 2 Circuit

DTC P0222
Throttle Position (TP) Sensor 2 Circuit Low Voltage

DTC P0223
Throttle Position (TP) Sensor 2 Circuit High Voltage

DTC P2135
Throttle Position (TP) Sensor 1-2 Correlation

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection






TYPICAL SCAN TOOL DATA

TP Sensor 1:




TP Sensor 2:






CIRCUIT/SYSTEM DESCRIPTION
The throttle actuator control (TAC) system uses two throttle position (TP) sensors to monitor the throttle position. The TP sensors 1 and 2 are located within the throttle body assembly. Sensor circuits consist of the following:
- A 5-Volt reference circuit
- A low reference circuit
- A TP sensor 1 signal circuit
- A TP sensor 2 signal circuit

Two processors are also used to monitor the TAC system data. Both processors are located within the engine control module (ECM). Each signal circuit provides both processors with a signal voltage proportional to throttle plate movement. The processors share and monitor data to verify that the indicated TP calculation is correct.

CONDITIONS FOR RUNNING DTC P0120, P0122, P0123, P0220, P0222, P0223
- The system voltage is more than 5.23 volts.
- The ignition is in the Unlock/Accessory or Run position.
- DTC P0641, P0651, or P0606 is not set.
- The DTCs run continuously when the above conditions are met.

CONDITIONS FOR RUNNING DTC P2135
- The system voltage is more than 5.23 volts.
- The ignition is in the Unlock/Accessory or Run position.
- DTC P0120, P0122, P0123, P0220, P0222, P0223, or P0606 is not set.
- The DTC runs continuously when the above conditions are met.

CONDITIONS FOR SETTING DTC P0120
The ECM detects that TP sensor 1 voltage is less than 0.35 volt or more than 4.58 volts for more than 0.5 second.

CONDITIONS FOR SETTING DTC P0122
The ECM detects that TP sensor 1 voltage is less than 0.35 volt for more than 0.5 second.

CONDITIONS FOR SETTING DTC P0123
The ECM detects that TP sensor 1 voltage is more than 4.58 volts for more than 0.5 second.

CONDITIONS FOR SETTING DTC P0220
The ECM detects that TP sensor 2 voltage is less than 0.35 volt or more than 4.59 volts for more than 0.5 second.

CONDITIONS FOR SETTING DTC P0222
The ECM detects that TP sensor 2 voltage is less than 0.35 volt for more than 0.5 second.

CONDITIONS FOR SETTING DTC P0223
The ECM detects that TP sensor 2 voltage is more than 4.59 volts for more than 0.5 second.

CONDITIONS FOR SETTING DTC P2135
The ECM detects that the difference between TP sensor 1 and TP sensor 2 exceeds a predetermined value for more than 0.5 second.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
- 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.
- Under certain conditions the control module commands the engine OFF.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

CIRCUIT/SYSTEM VERIFICATION
1. With the ignition ON and the engine OFF, observe the DTC information on the scan tool.
- If DTC P0641 or P0651 is also set, diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle. Diagnostic Trouble Code Descriptions
2. With the accelerator pedal in the rest position, observe the TP sensor 1 parameter with the scan tool. The voltage should be between 4.58-0.35 volts.
- If the voltage is outside of the range, continue with Circuit/System Testing.
3. Observe the TP sensor 2 parameter with the scan tool. The voltage should be between 0.35-4.59 volts.
- If the voltage is outside of the range, continue with Circuit/System Testing.
4. Observe the TP sensors 1 and 2 parameter with the scan tool. The sensors should indicate Agree.
- If the sensors indicate Disagree, continue with Circuit/System Testing.
5. Clear the DTCs with a scan tool.
6. Turn OFF the ignition for 60 seconds.
7. Operate the vehicle within the conditions for running the DTCs.
8. With the ignition ON and the engine OFF, observe the previous TP sensor parameters and DTC information, with the scan tool.
- If DTC P0120 or P0220 is set, and all of the previous TP sensor parameters are normal, replace the ECM.
- If any of the previous TP sensor parameters are now abnormal or out of range, continue with Circuit/System Testing.

CIRCUIT/SYSTEM TESTING
1. Turn OFF the ignition.
2. Disconnect the throttle body harness connector.
3. With the ignition ON and the engine OFF, observe the TP Sensor 1 parameter on the scan tool. The voltage should be less than 0.1 volt.
- If the voltage is more than 0.1 volt, test the TP sensor 1 signal circuit for a short to voltage or a faulty ECM.
4. Observe the TP Sensor 2 parameter on the scan tool. The voltage should be more than 4.8 volts.
- If the voltage is less than 4.8 volts, test the TP sensor 2 signal circuit for a short to ground or a faulty ECM.
5. Measure for 4.8-5.2 volts between the 5-Volt reference circuit and the negative terminal of the battery.
- If the voltage is more than 5.2 volts, test the 5-Volt reference circuit for a short to voltage or faulty ECM.
- If the voltage is less than 4.8 volts, test the 5-Volt reference circuit for an open, short to ground, or a faulty ECM.
6. Install a 3-amp fused jumper wire between the signal circuit and the 5-Volt reference circuit of the TP sensor 1. Observe the TP Sensor 1 parameter on the scan tool. The voltage should be more than 4.8 volts.
- If the voltage is less than 4.8 volts, test the TP sensor 1 signal circuit for an open, a short to ground, or a faulty ECM.
7. Install a test lamp between the signal circuit of the TP sensor 2 and the negative terminal of the battery. Observe the TP Sensor 2 parameter on the scan tool. The voltage should be less than 0.1 volt.
- If the voltage is more than 0.1 volt, test the TP sensor 2 signal circuit for an open or a faulty ECM.
- If test lamp illuminates, test the TP sensor 2 signal circuit for a short to voltage or faulty ECM.
8. Turn OFF the ignition.
9. Disconnect the ECM harness connector, and measure the 5-Volt reference, the low reference, and each of the signal circuits between the ECM and the throttle body for less than 5 ohms.
- If the resistance is more than 5 ohms, repair the affected circuit.
10. Test the signal circuits for continuity between them.
- If continuity exists between the signal circuits, repair the short.
11. If all circuits test normal, replace the throttle body.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Control Module References for ECM replacement, setup, and programming.
- Throttle Body Assembly Replacement Verification Tests
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