Diagnostic article Generic OBD-II
P2108: throttle module performance covers internal integrity tests
GM P2108 can arise from several internal throttle-control module checks, including memory, processor sequencing and excessive running resets.
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Documented application
GM 2009 09OBDG09 Engine Diagnostics, cited TAC module internal performance monitor only. Individual vehicle, engine, wiring and calibration applicability has not been established from this parameter file.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P2108 is an internal throttle actuator control module performance diagnostic in this GM example. The source lists several alternative integrity failures. The code is therefore broader than a single throttle-position sensor problem or a mechanical blade obstruction.
Different internal checks can produce the same record
Examples include unsuccessful memory read/write checks, a ROM checksum mismatch, disagreement between redundant stored values, incorrect program sequencing and excessive running resets. The table permits any listed failure path to produce the diagnostic; it does not require every internal test to fail together.
The timing also differs by path. Some checks occur at startup, while others recur during operation. The running-reset path uses ten occurrences in an ignition cycle. The stated prerequisites include sufficient ignition voltage, Run or Crank state and valid TAC-module-to-PCM serial data.
Do not infer a particular memory defect
Preserve the controller identity, supply context, communication status and any available detailed test information. The single code cannot distinguish a ROM integrity failure from a reset-history problem without further evidence. Redundant pedal calculations named in an internal test likewise do not automatically condemn the physical pedal assembly.
The table gives no universal module replacement instruction or programming procedure. Correct vehicle-specific diagnostics must establish the relevant failure path and any conditions contributing to it. Verification should address that path and its evaluation timing, rather than relying only on an erased record or a momentary normal throttle response.
Source and applicability
GM 2009 09OBDG09 Engine Diagnostics, cited TAC module internal performance monitor only. Individual vehicle, engine, wiring and calibration applicability has not been established from this parameter file.
General Motors source, physical page 50 · General Motors source, physical page 51
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Throttle Actuator A Control Module Performance
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT