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	P06A3	--	P0122, P0222,	P0223, P06A3, P2135	--
TP Sensor 1 Signal	P0122	P2119, P2135, P2176	P0122	P0123, P2135	P2135
TP Sensor 2 Signal	P0222	P2135	P0223	P0223, P2135	P2135
Low Reference	--	--	P0123, P0223	--	--

Typical Scan Tool Data

TP Sensor 1

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: The engine is idling. Parameter Normal Range: TP Sensor 1 3.8-4.4 V
5-Volt Reference	0.00 V	0.00 V	5.00 V
TP Sensor 1 Signal	0.00 V	0.00 V	5.00 V
Low Reference	--	4.98 V	--

TP Sensor 2

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: The engine is idling. Parameter Normal Range: TP Sensor 2 0.75-1.02 V
5-Volt Reference	0.02 V	0.00 V	5.00 V
TP Sensor 2 Signal	0.00 V	5.00 V	5.00 V
Low Reference	--	5.00 V	--

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 decreases and TP sensor 2 signal voltage increases as the accelerator pedal increases to wide open throttle (WOT).

Conditions for Running the DTC

P0121

P0122, P0123, P0222, P0223

P2135

Conditions for Setting the DTC

P0121

The ECM detects that the TP sensor 1 voltage is stuck in range for less than 1 second.

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 4.6 volts for less than 1 second.

P2135

The ECM detects that TP sensor 1 and TP sensor 2 disagree greater than 5 percent for less than 1 second.

Action Taken When the DTC Sets

P0121

P0122, P0123, P0222, P0223, or P2135

Conditions for Clearing the DTC

Diagnostic Aids

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

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 P06A3 is not set.

⇒	If the DTC is set, refer to DTC P0641, P0651, P0697, or P06A3.

2. Ignition ON, observe both TP Sensor voltage parameters with a scan tool. Verify the scan tool TP sensor parameters are between 0.50-4.5 V.
3. Observe the scan tool TP sensor 1 and 2 Agree/Disagree parameter while performing the following tests:

•	Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times.

•	Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times.

•	The TP sensor 1 and 2 Agree/Disagree parameter should display Agree.

4. Observe the DTC Information with a scan tool. DTCs P0121, P0122, P0123, P0221, P0222, and P0223 should not set.
5. Observe both TP Sensor percentage parameters while quickly pressing the accelerator pedal from a closed throttle to WOT. Both TP Sensor percentage parameters should change.
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 for 1 minute, test for less than 5 Ω between the low reference circuit terminal E 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 V between the 5-volt reference circuit terminal C 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. Test for less than 1 volt between the TP sensor 1 signal circuit terminal F and ground.

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

5. Test for 4.8-5.2 V between the TP sensor 2 signal circuit terminal D and ground.

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

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

6. Install a 3 A fused jumper wire between TP sensor 1 signal circuit terminal F and the 5-volt reference circuit terminal C. Verify the scan tool TP sensor 1 voltage parameter is greater than 4.8 V.

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

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.