P2310

P2310 means the PCM detected a high-voltage condition on the primary control circuit of ignition coil D — the IGT command line is reading higher than the expected 0-5V (or 0-12V) reference, the coil's internal driver is failing to pull the line to ground when commanded, or the PCM's current-sense feedback never sees the expected 5-15A primary current ramp during the 2-6 ms dwell. Cheapest-first ladder: (1) Visually inspect the coil D connector for backed-out pins, green corrosion, and a chafed wire shorted to a 12V source — a pinched wire rubbed through to a 12V circuit is a textbook P2310 cause. (2) Ohm the primary winding pin-to-pin — 0.4-1.5 ohms normal; an open primary (OL) often presents as a high-side code because the PCM sees the IGT line stuck high with no current flowing. (3) Scope the IGT trigger pulse — expect a clean 0-5V (or 0-12V) square wave with 2-6 ms dwell; if the trigger pulse is present but the line never collapses to ground, the coil's internal driver transistor is open-failed. (4) On platforms with an external ignition module, verify the module's ground and current-feedback signal lines. Expensive-misdiagnosis caveat: swap coil D with an adjacent coil and clear the code — if P2310 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.

Vehicle-specific patterns: 2001-2007 GM LSx V8 (LS1/LS2/LS6 in Camaro SS, Corvette, GTO) sees P2310 most often from OEM coil-pack pigtail insulation cracking against the valve-cover bracket — repair the pigtail rather than replacing the full harness. 2004-2010 Ford 4.6L/5.4L 3V Triton throws P2310 when the long extension boot allows secondary spark to track back up to the primary terminals and damage the internal driver — replace the boot at every plug service to prevent recurrence. 2011+ Ford 5.0 Coyote (Mustang GT, F-150) sees high-side primary codes from melted connectors when underhood temps run high under sustained load. 2007-2018 Toyota 2GR-FE / 2AZ-FE rarely throws P2310 before 100K miles; when it does, the failure is usually the coil itself rather than the harness. Mercedes M271 (1.8L supercharged 4-cyl, 2003-2012 C-Class/E-Class) and M273 (5.5L V8, 2007-2014 E-Class/S-Class/CLS) coil primary failures cluster at 80-120K miles with multiple TSBs around coil-pack heat shielding on the M273. Mazda RX-8 Renesis rotary trailing/leading coil failures appear earlier (50-70K miles) because of high rotor firing frequency. Common pattern: coil D usually = cylinder 4 or 6 on most platforms but can vary — verify against the OEM wiring diagram before swap-testing. Estimated repair: $40 (single coil DIY) to $400 (full set on a V8).