P0E65: Charger control-line hardware has reported a fault

P0E65 concerns the battery charger control circuit/open. In the 2018 GM HPC2/VICM table, the diagnostic evaluates the command line's hardware input/output fault flag rather than directly measuring delivered charging power.

A valid flag is part of the test

The failure condition is a true command-line fault flag. The charger enable mask must be true, system voltage at least 10.2 V, global diagnostic disable false, and the hardware flag not indeterminate. Thirty failed evaluations among 40 samples, at 25 milliseconds each, meet the one-second evaluation. GM specifies Type B, two trips.

The generic code description includes an open circuit, but the table does not supply a specific open-circuit voltage or a uniquely identified failed part. Keep the supported conclusion bounded to the control-circuit fault indication.

What changes interpretation

A charger that is not enabled does not reproduce the stated assessment conditions. Likewise, an unknown flag state cannot be treated as a clean passing result. Preserve charger enable, hardware status and supply context before clearing the fault.

Use the applicable control-circuit procedure to separate the output path, wiring and charger-side behavior. Following repair, confirm a determinate nonfaulted result while the test is enabled and complete the required charging checks. This code alone does not authorize replacing the charger or traction battery. Electrical access must follow qualified high-voltage service procedures, without improvised control-line energization.

Source and applicability

This explanation follows the documented GM monitor, not a verified application to every vehicle with this code. Confirm the vehicle, reporting module and calibration in current service information. GM diagnostic table, physical page 1013.