P2176

DTC P2176

Circuit Description

The engine control module (ECM) controls the throttle blades by applying a varying voltage to the throttle valve motor. The ECM monitors the actual throttle blade position using the throttle position (TP) sensors 1 and 2. If the ECM cannot detect the throttle position, DTC P2176 sets.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The control module cannot determine the throttle position.

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 and/or the Failure Records.
^ The control module commands the TAC system to operate in the Reduced Engine Power mode.
A message center or an indicator displays Reduced Engine Power.
^ Under certain conditions the control module commands the engine 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.

Diagnostic Aids

^ Inspect for a condition in which the throttle valves may be held open.
^ Inspect for conditions in which ice may have formed in the throttle bore.
^ The throttle valves are spring loaded to a slightly open position. This is referred to as the rest position. The throttle valves should not be completely closed, nor should they be open any more than the specified amount. The throttle valves should move to the open and 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 Special Functions. Actuate the throttle valves using the Throttle Position function located in the TAC system menu. This function will operate the throttle valve through the entire range in order to determine if the throttle body and system operate correctly.