GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2008 🢒 LaCrosse 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P2176

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 P2176: Minimum Throttle Position Not Learned

Circuit/System Description

The engine control module (ECM) controls the throttle valve by applying a varying voltage to the throttle actuator control (TAC) motor. The ECM monitors the actual throttle valve position using throttle position (TP) sensor 1 and 2.

Conditions for Running the DTC
    • The engine speed is less than 40 RPM.
    • The vehicle speed is 0 km/h (0 mph).
    • The engine coolant temperature (ECT) is between 5-85°C (41-185°F).
    • The intake air temperature (IAT) is between 5-60°C (41-140°F).
    • The accelerator pedal position (APP) sensor angle is less than 15 percent.
    • The ignition voltage is greater than 10 volts.
    • DTC P2176 runs once an ignition cycle when the above conditions are met for greater than 1 second.

Conditions for Setting the DTC
    • The ECM detects that the TP sensor 1 voltage is not between 0.21-0.89 volts during the throttle learn procedure.
        OR
    • The ECM detects that the TP sensor 2 voltage is not between 4.14-4.84 volts during the throttle learn procedure.
        OR
    • The minimum throttle position is not learned after an ECM replacement.
    • Any of the above conditions exist for greater than 4 seconds.

Action Taken When the DTC Sets

DTC  P2176 is a Type A DTC.

Conditions for Clearing the DTC

DTC P2176 is a Type A DTC.

Circuit/System Verification
  1. Ignition ON, rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release the pedal. Repeat the procedure several times. Observe the scan tool DTC information . Verify that DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0638, or P2101 do not set.
    2. ⇒If any of the above DTCs set, refer to Diagnostic Trouble Code (DTC) List - Vehicle DTC P0121, P0122, P0123, P0221, P0222, or P0223 for further diagnosis.
  2. DTC P2176 is an informational DTC. Perform the idle learn procedure, refer to Idle Learn .
    3. ⇒If DTC P2176 resets after performing the idle learn procedure, replace the throttle body.
  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 are captured in the Freeze Frame/Failure Records Data List.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Throttle Body Assembly Replacement