For 1990-2009 cars

## DTC P0122, P0123, P0222, P0223, or P2135 w/ Throttle ActuatorControl

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provide an overview of each diagnostic category.

### 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

• | The ignition is ON or the engine is operating.

• | The DTCs runs continuously when the above condition is met.

### 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

• | DTC P0122 and P0123 are type B DTCs

• | The ECM uses TP sensor 2 for throttle control.

#### P0222 or P0223

• | DTC P0222 and P0223 are type B DTCs

• | The ECM uses TP sensor 1 for throttle control.

#### P2135

• | DTC P2135 is a type A DTC.

• | The ECM commands the throttle actuator control (TAC) system to operate in a Reduced Engine Power mode.

• | The ECM commands the reduced engine power indicator ON.

### Conditions for Clearing the DTC

• | DTCs P0122, P0123, P0222, and P0223 are type B DTCs.

• | DTC P2135 is a type A DTC.

### Diagnostic Aids

• | If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected.

• | The scan tool 5 volt reference parameter should display between 4.8-5.2 volts.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### Description and Operation

Throttle Actuator Control (TAC) System Description

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Ignition ON, observe the DTC information with a scan tool. Verify DTC P0641 is not set.

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

2. Ignition ON, observe the TP Sensor percentage parameters with a scan tool. Verify the TP sensors 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. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

### 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 and ground.

⇒ | If greater than the specified value, test the low reference circuit for a short to voltage, or an open/high resistance. If the circuit/connections test normal, replace the ECM.

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

⇒ | If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM.

⇒ | If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

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

⇒ | If TP sensor 1 is greater than the specified range, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

⇒ | If TP sensor 1 is less than the specified range, test the signal circuit for a short to ground. If the circuit/connections test normal, replace the ECM.

⇒ | If TP sensor 2 is less than the specified range, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

⇒ | If TP sensor 2 is greater than the specified range, test the signal circuit for a short to ground. If the circuit/connections test normal, replace the ECM.

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

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

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

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

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Throttle Body Assembly Replacement

• | Control Module References for ECM replacement, setup, and programming

## DTC P0122, P0123, P0222, P0223, or P2135 w/o Throttle Actuator Control

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provide an overview of each diagnostic category.

### 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

• | The ignition is ON or the engine is operating.

• | The DTCs runs continuously when the above condition is met.

### 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

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Start the engine. Observe the TP Sensor voltage parameter with a scan tool. The parameter should be between 0.4-4.5 volts.
2. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the TP sensor.
2. Ignition ON, verify that the TP sensor voltage parameter is less than 0.3 volt.

⇒ | If greater than 0.3 volt, test the signal circuit of the TP sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.

Important: The test lamp is used to load the circuit and may not illuminate.

3. Ignition ON, connect a test lamp between the 5-volt reference circuit of the TP sensor and a good ground.

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.

4. Test for 4.8-5.2 volts between the 5-volt reference circuit of the TP sensor and a good ground.

⇒ | If less than 4.8 volts, test the 5-volt reference circuit of the TP sensor for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM.

⇒ | If greater than 5.2 volts, test the 5-volt reference circuit of the TP sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.

5. Ignition ON, test for less than 0.2 volt between the low reference circuit of the TP sensor and a good ground.

⇒ | If greater than 0.2 volt, test the low reference circuit of the TP sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.

6. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit of the TP sensor and a good ground.

⇒ | If greater than 5 ohms, test the low reference circuit of the TP sensor for an open/high resistance. If the circuit/connections test normal, replace the ECM.

7. Ignition ON, install a 3A fused jumper wire between the signal circuit and the 5-volt reference circuit of the TP sensor to verify that the TP sensor voltage parameter is greater than 4.8 volts.

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

8. If all circuits/connections test normal, test or replace the TP sensor.

### Component Testing

1. Turn OFF the ignition.
2. Measure for 5,150-5,350 ohms between the 5-volt reference and the low reference terminals of the TP sensor .

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

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

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

4. Apply 5 volts and ground to the applicable terminals of the TP sensor, and measure the voltage between the signal and the low reference terminals. Slowly sweep the TP sensor through the entire range several times. The voltage should vary between 0.6-4.7 volts without any spikes or dropouts.

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Throttle Body Assembly Replacement

• | Control Module References for engine control module replacement, setup, and programming