P2433: High secondary-air pressure signal is not proof of high airflow

A high secondary-air pressure reading and P2433 are not interchangeable findings. In the cited GM monitor, P2433 means the sensor voltage exceeded 4.501 V. The table describes this branch as high or open-circuit continuity, so an electrical interruption can be relevant even when the code wording says “high.”

Read the signal before interpreting pressure

The low-side partner, P2432, uses a boundary below 0.498 V. Together these monitors define electrical limits around the signal. They do not measure pump volume, establish exhaust restriction or prove that the pressure sensing element is defective.

If a recorded event contains both an implausible pressure value and an excessive sensor voltage, the voltage fault changes the interpretation: the displayed pressure may be the consequence of an invalid input. Treating it as trustworthy mechanical evidence can send diagnosis toward the wrong part of the AIR system.

Timing and verification

The source lists continuous monitoring, a 0.5-second enable interval and 0.2-second fault recognition, with a two-driving-cycle illumination strategy. A brief event can therefore matter even when the input looks normal during a later inspection. Preserve available event data instead of treating a current normal voltage as proof that no fault occurred.

Verification should distinguish a signal that has returned to the accepted electrical range from an AIR system that has passed its separate flow checks. This historical calibration supplies neither a connector pinout nor universal model coverage; use vehicle-specific electrical information before assigning an open circuit, reference problem or sensor replacement.

Source and applicability

GM 2009 09OBDG04 Engine Diagnostics, only the cited secondary-air monitor. The file does not establish the applicability of this code to a particular model or engine; thresholds are calibration-specific.

General Motors source, physical page 6