Diagnostic article Generic OBD-II
P2484: EGT sensor 5 intermittent signal and temperature-step evidence
Learn how GM P2484 qualifies rapid EGT sensor 5 changes, why filtered readings can miss them and which faults inhibit the test.
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.
The documented P2484 monitor examines unusually fast changes in exhaust gas temperature sensor 5. Its target is signal behavior, not simply a temperature that is too high or too low. Internal sensor problems, harness deterioration and connection issues are listed as possible explanations, requiring further evidence to separate them.
What the controller counts
The absolute raw temperature difference must exceed 100°C. Twelve failed samples within 25 samples qualify the event, with a 100 ms function task. The reporting classification is Type B, two trips. A single anomalous displayed number and a series of qualifying raw changes are therefore different diagnostic observations.
The unfiltered temperature must be within the printed 140–1,070 range. Initialization must be complete, run/crank and supply conditions acceptable, and the engine outside cranking. A communication error or an electrical fault affecting sensor 5 prevents the stated enable conditions from being met.
Build evidence around the intermittent event
Use a temperature trace that preserves short changes and record diagnostic status at the same time. Heavy averaging can make a discontinuous raw signal appear smooth, while a reading captured after the event may look entirely plausible. Compare timing with available neighboring exhaust-temperature channels to distinguish an isolated channel step from a broader operating change.
If an electrical-range or communication code accompanies P2484, determine which condition occurred first. A suppressed quick-change monitor is not evidence that the sensor's signal is healthy. Confirm the physical probe and connector assigned to sensor 5 from the applicable wiring information; this source does not map that index to a universal exhaust location or prescribe replacing the probe.
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 1207.
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 5
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