P2300
Ignition Coil A Primary Control Circuit Low
The primary control circuit of ignition coil A reads a voltage below the expected level — usually a short to ground on the primary driver wire or a low-resistance fault in the coil primary winding. Coil A cannot build a normal charge, so the cylinder it fires misfires, especially under load. Causes: short to ground in the primary wiring, an internal coil primary fault, or a faulty ECU/igniter driver.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- Internal coil shortCommon
- Primary wire shorted to groundPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Ignition Coil
- Coil Driver
- Ignition Wiring
P2300 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.