DTC P0122, P0123, P0222, P0223, or P2135 w/TAC

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

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

Diagnostic Fault Information

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
5-Volt Reference	P0122, P0222, P0641, P2106, P2110	--	P0122, P0222, P2106, P2110, P2135	P0223, P0641, P2106, P2110, P2135	--
TP Sensor 1 Signal	P0122, P2135	P2135	P0123, P2135	P0123, P2135	P2135
TP Sensor 2 Signal	P0222, P2135	P2135	P0222, P2135	P0223, P2135	P2135
Low Reference	--	--	P0123, P2106, P2110	--	--

Typical Scan Tool Data

TP Sensor 1

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: The ignition is ON and the engine is OFF. Parameter Normal Range: TP Sensor 1 7-21%
5-Volt Reference	0%	0%	30-40%
TP Sensor 1 Signal	0%	80-90%	85-99%
Low Reference	--	85-95%	--

TP Sensor 2

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: The ignition is ON and the engine is OFF. Parameter Normal Range: TP Sensor 2 7-21%
5-Volt Reference	80-90%	80-90%	0%
TP Sensor 2 Signal	80-90%	80-90%	0%
Low Reference	--	0%	--

Circuit/System Description

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 increases from below 1 volt at idle to above 4 volts at wide open throttle (WOT). TP sensor 2 signal voltage decreases from above 4 volts at idle to below 1 volt at WOT.

Conditions for Running the DTC

Conditions for Setting the DTC

P0122

The ECM detects that the TP sensor 1 voltage is less than 0.3 volt for less than 1 second.

P0123

The ECM detects that the TP sensor 1 voltage is greater than 4.8 volts for less than 1 second.

P0222

The ECM detects that the TP sensor 2 voltage is less than 0.3 volt for less than 1 second.

P0223

The ECM detects that the TP sensor 2 voltage is greater than 4.8 volts for less than 1 second.

P2135

The ECM detects that TP sensor 1 and TP sensor 2 disagree greater than 4.5 percent for less than 1 second.

Action Taken When the DTC Sets

P0122 or P0123

P0222 or P0223

P2135

Conditions for Clearing the DTC

Diagnostic Aids

Reference Information

Schematic Reference

Engine Controls Schematics

Description and Operation

Throttle Actuator Control (TAC) System Description

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 DTC information with a scan tool. Verify DTC P0641 is not set.

⇒	If P0641 is set, refer to DTC P0641 or P0651.

2. Ignition ON, observe the TP Sensor percentage parameters with a scan tool. Verify the scan tool TP sensors parameters are between 7-21 percent.
3. Observe both TP Sensor percentage parameters while pressing the accelerator pedal from a closed throttle to WOT. Both TP Sensor percentage parameters should change.
4. Rapidly depress the accelerator pedal from the rest position to the WOT position and release pedal. Repeat the procedure several times. DTCs P0122, P0123, P0222, P0223, or P2135 should not set.
5. Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. DTCs P0122, P0123, P0222, P0223, or P2135 should not set.
6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. 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 assembly.
2. Ignition OFF, test for 5 ohms or less of resistance between the low reference circuit terminal 4 and ground.

⇒	If greater than the specified range, test the low reference circuit for a short to voltage, or 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 1 and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the ECM.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Verify both scan tool TP sensor percentage parameters are between 80-88 percent.

•	If TP sensor 1 is less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.

•	If TP sensor 1 is greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

•	If TP sensor 2 is less than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

•	If TP sensor 2 is greater than specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.

5. If less than the specified range, test the appropriate signal circuit for a short to ground. If the circuit tests normal, replace the ECM.

⇒	If greater than the specified range, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

6. Install a 3A fused jumper wire between TP sensor 1 signal circuit terminal 3 and ground. Verify the scan tool TP sensor 1 percentage parameter is less than 2 percent.

⇒	If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

7. Install a 3A fused jumper wire between TP sensor 2 signal circuit terminal 2 and the 5-volt reference circuit terminal 1. Verify the scan tool TP sensor 2 percentage parameter is less than 2 percent.

⇒	If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

8. If all circuits test normal, test or replace the throttle body assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

DTC P0122, P0123, P0222, P0223, or P2135 wo/TAC

Diagnostic Instructions

DTC Descriptors

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

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

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5-Volt Reference	P0122	P0122	P0122	--
TP Sensor Signal	--	P0122	P0123	--
Low Reference	--	P0123	--	--

Typical Scan Tool Data

TP Sensor

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: The engine is operating in Closed Loop. Parameter Normal Range: TP Position Sensor 5%/4.2 Volts
5-Volt Reference	6%/0.40 Volts	6%/0.00 Volts	14%/5.00 Volts
TP Sensor Signal	6%/0.00 Volts	6%/0.00 Volts	6%/5.00 Volts
Low Reference	--	6%/5.00 Volts	--

Circuit/System Description

The throttle body assembly contains a throttle position (TP) sensor. The TP sensor is mounted externally on the throttle body assembly. The TP sensor is a potentiometer which provides a signal voltage that changes relative to the throttle blade angle. The engine control module (ECM) supplies the TP sensor with a 5-volt reference circuit, a low reference circuit, and a signal circuit. The TP sensor signal voltage decreases from less than 1 volt at idle to greater than 4 volts at wide open throttle (WOT).

Conditions for Running the DTC

Conditions for Setting the DTC

Important: The scan tool displays a voltage near 0.0 volts. Do not use the scan tool voltage parameter to determine if there is a TP sensor condition.

P0122

The ECM detects that the TP sensor voltage is less than 0.14 volt for greater than 5 seconds.

P0123

The ECM detects that the TP sensor voltage is greater than 4.9 volts for greater than 5 seconds.

Action Taken When the DTC Sets

DTC P0122 and P0123 are Type A DTCs.

Conditions for Clearing the DTC

DTC P0122 and P0123 are Type A DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

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. Engine running, observe the scan tool TP Sensor voltage parameter. The parameter should be between 0.4-4.5 volts.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. 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 TP sensor.
2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal B and ground.

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

Important: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.

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

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the ECM.

⇒	If greater than the specified range, 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 voltage parameter is less than 0.3 volt.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

5. Install a 3A fused jumper wire between the signal circuit terminal C and the 5-volt reference circuit terminal A. Verify the scan tool TP sensor voltage parameter is greater than 4.8 volts.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the ECM.

6. If all circuits test normal, test or replace the TP sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the TP sensor.
2. Test for 5,150-5,350 ohms of resistance between the 5-volt reference terminal A and the low reference terminal B.

⇒	If not within the specified range, replace the TP sensor.

3. Slowly sweep the sensor through the entire range several times while monitoring the resistance between the signal terminal C and the low reference terminal B. The resistance should vary between 2,500-6,800 ohms without any spikes or dropouts.

⇒	If not within the specified range or is erratic, replace the TP sensor.

4. Slowly sweep the TP sensor through the entire range several times while applying 5 volts and ground to the applicable terminals. Test the voltage between the signal terminal C and the low reference terminal B. The voltage should vary between 0.6-4.7 volts without any spikes or dropouts.

⇒	If not within the specified range or is erratic, replace the TP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.