P2300: Cylinder 1 ignition control circuit has a low electrical fault

P2300 is the cylinder 1 ignition-control circuit-low diagnosis in the reviewed GM source. The dictionary uses ignition coil A, while the OEM row names ignition control number 1. That mapping is limited to this implementation and does not establish a universal physical cylinder location.

What is supported by the table

The controller uses output-driver voltage to identify a short-to-ground signature. The listed design specification is less than 100 ohms between the signal and controller ground. This is a controller detection specification, not an instruction to test resistance on an operating ignition circuit.

The monitor requires the engine running and ignition voltage above 11 V. It counts 50 failures out of 63 samples at a 100-millisecond rate, with Type A, one-trip behavior.

A command-state inconsistency remains

The strategy says the low-side driver checks this fault when powered off, but the malfunction column says the driver is on. The electrical fault direction is clear; the exact state used for a reproduction test needs confirmation in applicable service information.

Retain command-state evidence and voltage conditions rather than assuming any low signal establishes the stored fault. Also separate this electrical diagnosis from a combustion diagnosis: it does not prove a worn spark plug, a secondary-ignition insulation failure or a mechanical cylinder problem.

Professional verification should confirm correct ignition-control electrical behavior under the vehicle's specified test and completion without recurrence. The summary does not identify the defective component or prescribe coil replacement.

Source and applicability

Use these facts only after confirming the documented system and calibration for the vehicle. GM diagnostic table, PDF page 640.