P216B: Group E low supply requires an on-state driver fault

P216B is the low supply-circuit entry for injector group E. The GM implementation labels the monitored output injector 5 high-side driver. It assesses feedback when that output is on and classifies the electrical behavior as a connection toward ground.

The diagnostic is about the energized path

A driver that is deliberately off is not expected to produce the same feedback as an energized one. The important record therefore aligns the high-side command with the abnormal status, rather than treating every low voltage as this fault. The code does not directly measure injector flow or low fuel pressure.

The source requires battery voltage of at least 11 V and absence of the specified P062B fault states. Its runtime condition is listed as at least zero seconds; no additional warmup delay is invented. Confirmation uses ten failures within twenty samples at 100 milliseconds per sample, with one-trip reporting.

Keep channel mapping and fault eligibility separate

Group E and the document's injector-5 label identify the monitored path within their respective naming systems. They do not establish a physical cylinder location for every vehicle carrying this generic code. Confirm the actual controller mapping before selecting hardware.

An inhibited driver assessment is not a passing assessment. Retain the wider injector-control fault state with command and supply information. The table does not identify where the ground-directed path occurs or provide a universal connector test, so the matching service procedure remains necessary for repair decisions.

Source and applicability

2025 GM 06B 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 439.