P2100

DTC P2100

Circuit Description

The engine control module (ECM) opens the throttle valve by applying a pulse width modulation voltage (PWM) to the throttle actuator control motor. The ECM reverses the polarity on the throttle actuator control motor control circuits in order to close the throttle valve. The ECM increases the pulse width as necessary to open the throttle valve. The ECM monitors throttle position (TP) sensors 1 and 2 to determine the actual throttle valve position. If the ECM detects that the output driver for the throttle actuator control (TAC) motor does not deactivate when commanded OFF, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2100 Throttle Actuator Control (TAC) Motor Control Circuit

Conditions for Running the DTC

* Before the ECM can report DTC P2100 failed, DTC P2101 must run and pass.
* The ignition is ON or the engine is operating.
* DTC P2100 runs continuously once the above conditions are met for more than 1 second.

Conditions for Setting the DTC

* The ECM detects the output driver for the TAC motor does not deactivate when commanded OFF.
* The condition exists for less than 4 seconds.

Action Taken When the DTC Sets

* The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
* The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

* The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs and does not fail.
* A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
* A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
* Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

* Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
* The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Engine Controls Component Views.
* 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. Observe the Freeze Frame/Failure Records.
* The throttle valve is spring loaded to a slightly open position. The throttle valve should be open approximately 3-5 percent. This is referred to as the rest position.
* The throttle valve should not be completely closed or open any more than a specified amount.
* The throttle valve should move open and to the closed position without binding under the normal spring pressure.
* The throttle should NOT be free to move open or closed WITHOUT spring pressure.
* The scan tool has the ability to operate the throttle control system using the TP function located in the TAC System menu. This function operates the throttle valve through the entire range in order to determine if the TAC system operates correctly.
* For an intermittent condition, Refer to Intermittent Conditions. Intermittent Conditions

Test Description

Step 1 - Step 7:

Step 8 - Step 18:

Step 19:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the condition exists. A TP sensor DTC may cause this DTC to set.
3. Depending on the condition, DTC P0638, P2100, P2101, and/or P2119 may set individually or together.
8. When the ignition is turned ON, the ECM operates the throttle actuator control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.