P2300

P2300 means the PCM detected a low-voltage condition on the primary control circuit of ignition coil A — the IGT (ignition trigger) command line from the PCM to the coil is reading lower than the expected reference (typically the PCM drives this line between 0V at rest and ~5V commanded, sometimes 12V depending on platform), or the primary current the PCM monitors on its current-sense feedback is well below the 5-15A peak it expects to see when the coil is charging. Cheapest-first ladder: (1) Pull the coil and inspect the connector for green corrosion, bent pins, and backed-out terminals — a 2-pin or 3-pin COP connector with one pin pushed back is the #1 cause and costs $0 to fix with a pick. (2) Ohm the primary winding pin-to-pin at the coil — spec is 0.4-1.5 ohms for most modern COP coils; reading 0.0 ohms is a shorted primary, OL/infinite is an open primary, both condemn the coil. (3) Backprobe the IGT wire at the coil with a scope while cranking — you should see a clean 0-5V (or 0-12V) square-wave trigger pulse with 2-6 ms dwell; missing pulse means the PCM driver or the harness between PCM and coil is the problem. (4) Check the 12V feed pin at the coil with key-on — should be battery voltage; low or absent feed traces back to the ignition relay or fusible link. Expensive-misdiagnosis caveat: swap coil A with the coil from an adjacent cylinder and clear the code — if the P2300 follows the coil to the new cylinder, it's the coil; if it stays on the original cylinder, it's the harness, connector, or PCM driver. A $40 coil swap-test saves the $80 misdiagnosis fee for replacing a coil that wasn't the problem.

Vehicle-specific patterns: 2005-2014 GM LSx V8 (LS1/LS2/LS3 in Silverado, Camaro, Corvette, GTO) mounts the COP coils directly on the valve covers where they cook from underhood and exhaust-manifold heat soak — primary windings open up around 80-120K miles and the driver-side bank (cylinders 1/3/5/7 on LS firing order) typically fails first because of proximity to the exhaust crossover. 2004-2010 Ford 4.6L/5.4L Triton 3-valve (F-150, Crown Vic, Expedition) uses a COP coil with a long extension boot down into a deep spark-plug well — the boot traps moisture and carbon-tracks, mimicking a primary fault on the scan tool; pull and inspect every boot before condemning a coil. 2011+ Ford 5.0 Coyote (Mustang GT, F-150) sees primary-circuit codes from melted COP connectors where the harness lays against the intake manifold. 2007-2018 Toyota 2GR-FE 3.5L V6 and 2AZ-FE 2.4L (Camry, Highlander, Sienna, RAV4) typically run 100-150K miles before primary failures appear, and when they do it's almost always a single coil rather than a set. Common pattern: ignition coil A usually = cylinder 1 on most Ford/GM/Toyota platforms, but it can vary (some PCMs label by firing-order position rather than cylinder number) — verify against the OEM wiring diagram before swap-testing. Estimated repair: $40 (single coil DIY) to $320 (full set of 8 COP coils + labor).