Diagnostic Instructions

DTC Descriptors

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

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
5-Volt Reference	P0122, P0222, P0641	--	P0122, P0222, P2135	P0223, P0641, 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, P2135	--	--

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

P0120, P0122, P0123, P0220, P0222, and P0223

Conditions for Running the DTC

P2135

Conditions for Setting the DTC

P0120

The ECM detects that the TP sensor 1 voltage is less than 0.3 volt or greater than 4.75 volts for greater than 1 second.

P0122

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

P0123

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

P0220

The ECM detects that the TP sensor 2 voltage is less than 0.25 volt or greater than 4.6 volts for greater than 1 second.

P0222

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

P0223

The ECM detects that the TP sensor 2 voltage is greater than 4.6 volts for greater than 1 second.

P2135

The ECM detects that TP sensor 1 and TP sensor 2 disagree greater than a predetermined value for greater than 1 second.

Action Taken When the DTC Sets

Conditions for Clearing the DTC

DTCs P0120, P0122, P0123, P0220, P0222, P0223, and P2135 are Type A DTCs.

Diagnostic Aids

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Engine Control Module 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 scan tool TP Sensor percentage parameters. 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 P0120, P0122, P0123, P0220, 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 P0120, P0122, P0123, P0220, 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 less than 5 ohms between the low reference circuit terminal C 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 E 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.

•	TP sensor 1 signal circuit terminal D

•	TP sensor 2 signal circuit terminal F

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 D 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 F and the 5-volt reference circuit terminal E. 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.