Diagnostic article Generic OBD-II
P2472: EGT sensor 4 intermittent signal and rapid-change monitoring
P2472 in this GM source evaluates rapid raw temperature changes at EGT sensor 4, with specific temperature gates and sample qualification.
Read before applying this article
Documented application
2025 GM 04A documented monitor only. Vehicle, engine and controller calibration applicability must be established separately; no model fitment is inferred from the 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.
P2472 is the quick-change monitor for exhaust gas temperature sensor 4 in this GM document. It detects a signal changing faster than the expected sensor dynamics. The listed possibilities include an internal sensor malfunction, deteriorated wiring and electrical connection problems; the code does not select one of those causes.
A change threshold, not a hot-exhaust limit
The failure comparison uses an absolute raw temperature difference greater than 100°C. That value describes change in the signal, not a maximum acceptable exhaust temperature. The function runs every 100 ms and requires 12 failed samples in a 25-sample set. Type B, two-trip behavior is specified.
The monitor is gated by an unfiltered temperature between 140 and 1,070, with the upper boundary continuing onto the next PDF page. The sensor initialization delay must have elapsed. Run/crank state and supply validity must be acceptable, cranking must be absent, and neither a communication error nor an electrical fault affecting the sensor may be active.
Collect a trace that preserves the event
Record the sensor's raw or least-filtered temperature, diagnostic status and available neighboring temperature channels with adequate time resolution. A slowly refreshed dashboard value can hide the short changes that this monitor counts. A steady high temperature is a different observation from repeated abrupt steps.
Check communication and direct electrical codes before interpreting a missing quick-change result: those conditions can inhibit this test. Establish which physical probe the vehicle assigns to sensor 4 using its service information. The summary does not locate the probe, and the index number alone is insufficient to order a sensor or identify a connector.
Source and applicability
2025 GM 04A documented monitor only. Vehicle, engine and controller calibration applicability must be established separately; no model fitment is inferred from the file. GM PDF, physical page 1201; GM PDF, physical page 1202.
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
Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic Bank 1 Sensor 4
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