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 59: Intake Air Flow Valve Control Circuit Malfunction
DTC P2101 39: Intake Air Flow Valve Control Circuit Internal Malfunction
DTC P2101 03: Intake Air Flow Valve Control Circuit Low Voltage
DTC P2101 51: Intake Air Flow Valve Control Circuit Malfunction
DTC P2101 54: Intake Air Flow Valve Control Circuit High Temperature
DTC P2101 52: Intake Air Flow Valve Control Circuit Malfunction

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Control X | P2102 02, P2101 03 | P2100 04, P2101 54 | P2103 01 | P2101 59, P2101 39, P2101 51, P2101 52
Control Y | P2102 02, P2101 03 | P2100 04, P2101 54 | P2103 01 | P2101 59, P2101 39, P2101 51, P2101 52

### Circuit/System Description

A throttle plate actuator is used to achieve high exhaust gas recirculation rates. It increases the pressure difference between exhaust and intake so that the appropriate exhaust quantity can be mixed with the intake air. The ECM transmits the desired angle as a PWM signal to the throttle plate actuator. The throttle plate actuator operates the DC motor to control the throttle plate based on the PWM signal from the ECM. The throttle plate position is monitored by an internal position sensor.

### Conditions for Running the DTC

• | The ignition is ON, or the engine is running.

• | The throttle actuator motor is commanded ON or OFF.

• | The ignition voltage is less than 16 V.

• | The DTCs run continuously when the above conditions are met.

### Conditions for Setting the DTC

The ECM detects an open, short to ground, or a short to voltage on the throttle actuator control circuit for greater than 1 s.

### Action Taken When the DTC Sets

DTC P2101 is a Type A DTC.

### Conditions for Clearing the DTC

DTC P2101 is a Type A DTC.

### 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. Ignition ON, command the Intake Air Flow Valve Position ON and OFF with a scan tool. The throttle plate should respond to the scan tool commands.
2. Observe the scan tool DTC information parameter. DTCs P2100, P2101, P2102 or P2103 should not set.
3. 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 Q38 Throttle Body.
2. Test for less than 5 Ω between the control circuit terminal 2 and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the K20 Engine Control Module (ECM).

3. Test for less than 5 Ω between the control circuit terminal 6 and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the K20 Engine Control Module (ECM).

4. Connect a test lamp between control circuit terminal 2 and control circuit terminal 6.
5. Command the Intake Air Flow Valve Position ON and OFF with a scan tool. The test lamp should respond to the scan tool commands.

⇒ | If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the K20 Engine Control Module (ECM).

6. 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