P2122: Accelerator pedal sensor 1 signal below its allowed range

P2122 identifies a low accelerator-pedal-position sensor 1 signal in the reviewed GM calibration. The generic dictionary describes sensor or switch D; the OEM row resolves that label to APP1. It is a pedal-input diagnosis, so a throttle-body fault should not be assumed from the catalog's broader wording.

Threshold and monitoring conditions

The controller flags APP1 below 9.25% of its reference scale, with 100% corresponding to five volts. This is a signal plausibility boundary, not the percentage of pedal travel. Confusing those two scales can make a normal released-pedal reading appear contradictory.

Run/crank voltage must exceed 6.41 V. The row also excludes a reference-voltage error associated with P06A3. A reference-supply problem can therefore affect whether this APP-specific diagnostic is allowed to run and should be considered when interpreting accompanying codes.

Continuous versus intermittent evidence

The source explicitly covers both a low short and an open circuit, so the word low does not uniquely establish a ground short. It also supports intermittent detection: the count criteria include 19 out of 39 samples or 14 continuous counts, evaluated every 12.5 milliseconds.

A present-day normal reading cannot erase a recorded brief dropout. Useful verification captures APP1 over time, together with reference-fault status and available supply voltage, using the vehicle-specific procedure. The table does not identify a connector, terminal, pedal replacement or safe-driving conclusion. It documents a Type A, one-trip diagnostic response for this calibration.

Source and applicability

This explanation is limited to the documented 2025 GM monitor; its thresholds are not universal vehicle specifications. GM diagnostic table, PDF page 597.