Diagnostic article Generic OBD-II
P064E: bank-2 oxygen-interface processor self-checks
P064E covers self-checks of the interface ASIC for bank-2 upstream oxygen sensor 1.
Read before applying this article
Documented application
2025 GM 25OBDG07A Part2 diagnostic monitor documentation; the application-matrix filename mismatch is unresolved, so no model or engine applicability is inferred.
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.
P064E covers self-checks of the interface ASIC for bank-2 upstream oxygen sensor 1. The documented monitor examines internal interface health rather than directly deciding whether the exhaust mixture is rich or lean.
Multiple internal reasons can set the code
The cited page includes an internal supply-undervoltage report, an active production-test access port, built-in self-test failure, sequencer-watchdog problems, program-ROM read errors, and an unsuitable chip-identification result. These are different diagnostic branches sharing the same processor-performance code.
The diagnosis register must be valid, and the controller applies battery-voltage and common enable conditions. An ASIC-reported internal undervoltage is therefore not automatically identical to a battery-terminal measurement made later; the reported supply event and the conditions for reading the register are distinct pieces of evidence.
Interpret before selecting a repair
Obtain the specific internal status or failure detail when the service system provides it. A circuit fault at the oxygen sensor and a failed interface self-test should not be collapsed into the same replacement decision.
The table lists a 0.01-second time and two-trip reporting. Verification should show a valid diagnosis-register read and completion of the relevant self-check without the triggering status. The base code alone does not prove that the oxygen sensor or the complete engine controller must be replaced.
Documentation and applicability
These details describe the monitor in GM’s 2025 25OBDG07A Part2 file. Its application-matrix filename does not match the download index, so model and engine applicability remain unresolved. Use the vehicle’s correct service information before applying these calibration details.
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
Internal Control Module O2 Sensor Processor Performance Bank 2
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