For 1990-2009 cars

### 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 provides an overview of each diagnostic category.

### DTC Descriptor

DTC P0221: Throttle Position (TP) Sensor 2 Performance
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 | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
TP Sensor 2 Signal | P0222 | P0223 | P0223 | P0221
TP Sensor 5V Reference | P0222 | P0222 | P0223 | --
TP Sensor Low Reference | -- | P0223 | -- | --

### Typical Scan Tool Data

#### TP Sensor 2

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Parameter Normal Range: 0.16-4.88 V
TP Sensor 2 Signal | 0 V | 5 V | 5 V
TP Sensor 5V Reference | 0 V | 0 V | 5 V
TP Sensor Low Reference | -- | 5 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 5V reference circuit, a common low reference circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. TP sensor 1 signal voltage decreases from above 4V at idle to below 1V at wide open throttle (WOT). TP sensor 2 signal voltage increases from below 1V at idle to above 4V at wide open throttle.

The ECM compares the signal of the TP sensor 1 and TP sensor 2 through the entire operating range.

### Conditions for Running the DTC

• | The system voltage is more than 7V.

• | The TP sensor 2 voltage is between 0.16-4.88V.

• | DTCs P0221, P0222, and P0223 run continuously when the above conditions are met.

### Conditions for Setting the DTC

#### P0221

• | The TP sensor 1 disagrees more than 6.3 percent from TP sensor 2 for over 140 ms.

• | The TP sensor 2 disagrees more than 9 percent from the throttle position calculated from mass air flow (MAF) signal for over 280 ms.

#### P0222

The TP sensor 2 voltage is less than 0.16V for over 140 ms.

#### P0223

The TP sensor 2 voltage is more than 4.88V for over 140 ms.

### Action Taken When the DTC Sets

• | DTC P0221 is a Type B DTC.

• | DTCs P0222 and P0223 are Type A DTCs.

• | The control module commands the TAC system to operate in the Reduced Engine Power mode.

• | A message center or an indicator displays Reduced Engine Power.

### Conditions for Clearing the DTC

• | DTC P0221 is a Type B DTC.

• | DTCs P0222 and P0223 are Type A DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component 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

Control Module References for scan tool information

### Circuit/System Verification

1. If DTC P0698 or P0699 are set, refer to DTC P0641-P0643, P0651-P0653, or P0697-P0699.
2. Ignition ON, observe the TP sensor 2 voltage parameter. The reading should be between 0.16-4.88V and change with accelerator pedal input.
3. 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.

### 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 5Ω between the low reference circuit terminal C and ground.

⇒ | If greater than 5Ω, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

3. Ignition ON, test for 4.8-5.2V between the 5V reference circuit terminal E and ground.

⇒ | If less than 4.8V, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

⇒ | If greater than 5.2V, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Verify the scan tool TP sensor 2 voltage is greater than 4.8V.

⇒ | If less than 4.8V, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the K20 ECM.

5. Install a 3A fused jumper wire between the signal circuit terminal F and the low reference circuit terminal C of the TP sensor 2. Verify the TP sensor 2 voltage is less than 0.1V.

⇒ | If greater than 0.1V, test the TP sensor 2 signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

6. Ignition OFF, disconnect the harness connector at the K20 ECM.
7. Test for less than 5Ω on the TP sensor 2 circuits between the following terminals:

• | ECM X1 5V reference circuit terminal 39 to terminal E.

• | ECM X1 signal circuit terminal 89 to terminal F.

⇒ | If greater than 5Ω, repair the affected circuit.

8. Test for infinite resistance between TP sensor 1 signal circuit terminal D and TP sensor 2 signal circuit terminal F.

⇒ | If less than infinite resistance, repair the short between TP sensor 1 signal circuit and TP sensor 2 signal circuit.

9. If all circuits test normal, replace the Q38 throttle body.

### 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