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 Descriptors

DTC P2101: Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
DTC P2119: Throttle Closed Position Performance

### Circuit/System Description

The engine control module (ECM) controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control (TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the throttle position (TP) sensors 1 and 2 to determine the actual throttle valve position

### Conditions for Running the DTC

#### P2101

• | The engine is running.

• | The ignition 1 voltage is greater than 10 volts.

• | The DTC runs continuously once the above conditions are met.

#### P2119

• | The ignition is cycled from OFF to ON.

• | The DTC runs continuously once the above condition is met.

### Conditions for Setting the DTC

#### P2101

The ECM detects that the commanded duty cycle is greater than 45 percent for 6 seconds.

#### P2119

The ECM detects that the commanded duty cycle is less than -42 percent for 6 seconds.

### Action Taken When the DTC Sets

DTCs P2101, and P2119 are Type A DTCs.

### Conditions for Clearing the DTC

DTCs P2101, and P2119 are Type A DTCs.

### 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

• | 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. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0122, P0123, P0222, or P0223 is not set.

⇒ | If any of the DTCs are set, refer to DTC P0121, P0122, P0123, P0221, P0222, or P0223 for further diagnosis.

2. Ignition ON, observe the scan tool TP Sensor percentage parameters. The reading should be between 7-21 percent.

⇒ | If not within the specified range, refer to DTC P0121, P0122, P0123, P0221, P0222, or P0223 for further diagnosis.

3. Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. DTCs P2101, or P2119 should not set.

⇒ | If DTCs P0122, P0123, P0222, P0223, or P2135 set while performing this procedure, refer to DTC DTC P0121, P0122, P0123, P0221, P0222, or P0223 for further diagnosis.

4. Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. DTCs P2101, or P2119 should not set.

⇒ | If DTCs P0122, P0123, P0222, P0223, or P2135 set while performing this procedure, refer to DTC P0121, P0122, P0123, P0221, P0222, or P0223 for further diagnosis.

5. 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. Verify the following conditions do not exist:

• | The throttle body is not damaged or modified

• | Vacuum leaks

• | A restricted air intake system

• | Excessive deposits on the throttle plate or bore

• | The throttle shaft for binding

• | The throttle linkage or the throttle cable for binding

• | Incorrectly installed positive crankcase ventilation (PCV) valve or hose

• | A malfunctioning PCV valve

⇒ | If you find any of the above conditions, repair as necessary.

2. Ignition OFF, disconnect the harness connector at the throttle body.

Important: Disconnecting the throttle body harness connector causes additional DTCs to set.

3. Ignition ON, test for less than 0.5 volt on the TAC motor control 1 circuit terminal 4 and TAC motor control 2 circuit terminal 2.

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

4. Connect a test lamp between motor control 1 circuit terminal 4 and motor control 2 circuit terminal 2 and B+. Verify the test lamp does not illuminate.

⇒ | If the test lamp illuminates, test the appropriate motor control circuit for a short to ground. If the circuit tests normal, replace the ECM.

5. Ignition OFF, connect the test lamp between the motor control 1 circuit terminal 4 and motor control 2 circuit terminal 2 of the throttle body harness connector. Observe the test lamp while turning the ignition ON for 5 seconds and then OFF. Verify the test lamp illuminates.

⇒ | If the test lamp does not illuminate, test each motor control circuit for an open or for a short between the motor control 1 and motor control 2 circuits. If the circuit tests normal, replace the ECM.

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