Diagnostic Instructions

DTC Descriptors

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

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

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

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

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
TP Sensor 1 Signal	P0122	P0123	P0123	P0068, P0121
TP Sensor 1 5-Volt Reference	P0122	P0122	P0123	--
TP Sensor 1 Low Reference	--	P0123	--	--
TP Sensor 2 Signal	P0222	P0222	P0223	P0068, P0121
TP Sensor 2 5-Volt Reference	P0222	P0222	P0223	--
TP Sensor 2 Low Reference	--	P0223	--	--

Typical Scan Tool Data

TP Sensor 1

Circuit	Short to Ground	Open	Short to Voltage
Parameter Normal Range: 0.20-4.82 V
TP Sensor 1 Signal	0 V	5 V	5 V
TP Sensor 1 5-Volt Reference	0 V	0 V	5 V
TP Sensor 1 Low Reference	--	5 V	--

TP Sensor 2

Circuit	Short to Ground	Open	Short to Voltage
Parameter Normal Range: 4.82-0.19 V
TP Sensor 2 Signal	0 V	0 V	5 V
TP Sensor 2 5-Volt Reference	0 V	0 V	5 V
TP Sensor 2 Low Reference	--	5 V	--

Circuit/System Description

The throttle actuator control (TAC) system uses 2 throttle position (TP) sensors to monitor the throttle position. The TP sensors 1 and 2 are located within the throttle body assembly. Each sensor has the following circuits:

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. Both processors monitor each other's data to verify that the indicated TP calculation is correct.

Conditions for Running the DTC

P0122, P0123, P0222, P0223

Conditions for Setting the DTC

P0122

The ECM detects that the TP sensor 1 voltage is less than 0.20 volt for more than 0.4 second.

P0123

The ECM detects that the TP sensor 1 voltage is more than 4.82 volts for more than 0.4 second.

P0222

The ECM detects that the TP sensor 2 voltage is less than 0.19 volt for more than 0.4 second.

P0223

The ECM detects that the TP sensor 2 voltage is more than 4.82 volts for more than 0.4 second.

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

DTCs P0122, P0123, P0222, P0223 are Type A DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Description and Operation

Throttle Actuator Control (TAC) System Description

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, observe the TP sensor 1 voltage parameter. The reading should be between 0.20-4.82 volts and change with accelerator pedal input.
2. Ignition ON, observe the TP sensor 2 voltage parameter. The reading should be between 0.19-4.82 volts and change with accelerator pedal input.
3. Observe the TP sensor 1 and 2 parameter. The scan tool should indicate Agree.
4. Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC, or within the conditions that you observed from the Freeze Frame/Failure Records.
5. Verify that DTCs P0642, P0643, P0652 or P0653 are not set.

⇒	If DTCs P0642, P0643, P0652 or P0653 are set, refer to DTC P0642, P0643, P0652, or P0653.

6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the throttle body. Allow sufficient time for the ECM to completely power down.
2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 6 and ground.

⇒	If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 2 and ground.

⇒	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.

4. Verify the scan tool TP sensor 1 voltage is greater than 4.8 volts.

⇒	If less than 4.8 volts, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the ECM.

5. Verify the scan tool TP sensor 2 voltage is less than 0.1 volt.

⇒	If greater than 0.1 volt, test the signal circuit terminal 4 for a short to voltage. If the circuit tests normal, replace the ECM.

6. Install a 3A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 6 of the TP sensor 1. Verify that the TP sensor 1 voltage is less than 0.1 volt.

⇒	If greater than 0.1 volt, test the TP sensor 1 signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

7. Install a 3A fused jumper wire between the signal circuit terminal 4 and the 5-volt reference circuit terminal 2 of the TP sensor 2. Verify the TP sensor 2 voltage is greater than 4.8 volts.

⇒	If less than 4.8 volts, test the TP sensor 2 signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

8. Ignition OFF, disconnect the harness connector at the ECM.
9. Test for less than 5 ohms on all TP sensor circuits between the following terminals:

•	The 5-volt reference circuit terminal 2 to the corresponding ECM terminal

•	The signal circuit terminal 1 to the corresponding ECM terminal

•	The signal circuit terminal 4 to the corresponding ECM terminal

⇒	If greater than 5 ohms, repair the affected circuit.

10. If all circuits test normal, replace the throttle body.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.