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.

DTC P2072

The ECM detects the throttle blade is stuck open or stuck closed for 1 second.

DTC P2072 is a Type A DTC.

DTC P2072 is a Type A DTC.

Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore causing the throttle valve not to close.

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

Special Tools

J 34730-405 Injector Test Lamp

1. Ignition ON, observe the DTC information with a scan tool. DTCs P0121, P0122, P0123, P0221, P0222, or P0223 should not set.

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

2. Verify TP sensor 1 voltage is between 0.4-0.9 volt, and TP sensor  2 voltage is between 4.1-4.7 volts.

⇒	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. DTC P2072 should not set.

⇒	If DTCs P0121, P0122, P0123, P0221, P0222, or P0223 set while performing this procedure, refer to 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. DTC P2072 should not set.

⇒	If DTCs P0121, P0122, P0123, P0221, P0222, or P0223 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.

1. Inspect the throttle body for the following conditions:

•	A throttle blade that is not in the rest position

•	A throttle valve that is binding open or closed

•	A throttle valve that opens or closes without spring pressure

⇒	If a condition is found, replace the throttle body.

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

2. Ignition OFF, disconnect the harness connector at the throttle body.
3. Install fused jumper wires between the throttle body and harness connector of the following circuits:

•	Low reference circuit terminal 3

•	5-volt reference circuit terminal 1

•	TP sensor 1 circuit terminal 4 or TP sensor 2 signal circuit terminal 2

4. Ignition ON, test for less than 0.5 volts on the motor control 1 circuit terminal 4 and 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.

Important: The scan tool TAC motor command is disabled, if multiple TP sensor or TAC circuit DTCs are set.

5. Ignition OFF, command the TAC motor with the scan tool, while measuring the voltage of the TAC motor control 1 circuit terminal 4 and TAC motor control 2 circuit terminal 2.

⇒	If the voltage changes between 0.0 volts to greater than 10.5 volts on both circuits, replace the throttle body.

⇒	If the voltage changes between 0.0 volts to less than 10.5 volts on either circuit, test for an open or a short to ground in the appropriate TAC motor control circuit.

⇒	If the circuits test normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.