GM Service Manual Online
For 1990-2009 cars only

Important: This DTC is used for information only.

If the engine control module (ECM) detects a condition in the throttle actuator control (TAC) system, the ECM disables the TAC motor. The accelerator pedal position (APP) sensor will have no affect on the throttle position and the throttle will remain in the rest position. The RPM will vary due to limited fuel and spark changes based on APP input. If the engine speed is above 1,300 RPM, the ECM will turn the fuel off for short intervals until the engine RPM is below 1,300 RPM. If the ECM detects a fault in the TAC system that is beyond its controllable limits, DTC P2105 sets.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

    • The ECM detects an error in the throttle actuator control system.
    • The engine speed is more than 1,120 RPM.
    • The condition exists for longer than 5 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.
    • The control module will cause the engine to turn OFF.

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 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.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Are DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0638, P1551, P2100, P2101, P2107, P2119, P2122, P2123, P2127, P2128, P2135, P2138, or P2176 also set?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

Replace the engine control module (ECM). Refer to Engine Control Module Replacement .

Did you complete the replacement?

Go to Step 4

--

4

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 5

5

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK