Diagnostic article Generic OBD-II
P2126: pedal channel two has an unresolved range classification
GM P2126 in this example identifies a channel-two signal outside its encoded range when the ordinary low/high fault classification is not available.
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Documented application
GM 2009 09OBDG06 Engine Diagnostics, cited accelerator channel-two rationality example only. Per-code vehicle, engine and calibration applicability has not been established; use the matching vehicle procedure.
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.
P2126 is the accelerator-position channel-two rationality code in this GM 2009 table. It is distinct from P2127 and P2128, the ordinary low- and high-circuit records. The source describes a monitoring path that detects an out-of-range signal but cannot resolve the normal minimum or maximum fault classification.
Channel two uses its own encoded range
The printed range is below 5 percent or above 50 percent, with a 100-millisecond evaluation. P2127/P2128 must not be set, pending or confirmed for the stated rationality condition. These percentages describe the table's signal representation, not a recommended physical pedal position.
The channel-one range in the same document is different. Applying its numbers to channel two would erase a meaningful distinction in this controller's evaluation. The correct scan-data and wiring definitions must establish which representation is being viewed.
Retain classification and controller context
A technician should preserve the exact code, companion-code states and available processor information. The table's abbreviated reference to a main-processor problem does not prove that controller hardware requires replacement. It describes a diagnostic classification, not a component-isolation result.
Likewise, a driver report of poor acceleration cannot establish this specific electrical event. The matching electronic-throttle procedure must determine whether the signal path and controller evaluation are trustworthy. The source provides no pinout, pedal replacement instruction or safe operating assurance. Verification needs a qualified evaluation of the affected channel, rather than only clearing its stored record.
Source and applicability
GM 2009 09OBDG06 Engine Diagnostics, cited accelerator channel-two rationality example only. Per-code vehicle, engine and calibration applicability has not been established; use the matching vehicle procedure.
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/Pedal Position Sensor/Switch E Circuit Range/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