P1366

P1366 is Acura's TDC Sensor 2 Intermittent code — the companion to P1361. The J35 V6 runs two TDC sensors for redundancy and for resolving which stroke each cylinder is on during sequential injection; sensor 2 typically lives a few inches from sensor 1 on the same target wheel housing or on the opposite cam, and the ECM compares the two signals to detect timing errors. P1366 means sensor 2 is dropping signal intermittently. Shop ladder, cheapest first: (1) Same as P1361 — inspect the TDC2 connector for oil intrusion from a weeping valve cover gasket, clean with contact cleaner, fix the gasket leak. (2) Scan live data and snap-throttle while watching the TDC2 Hall pulse on a scope — should be a clean 0-5V square wave with sharp edges at every cam-target tooth. Dropouts, ragged edges, or missing pulses confirm the sensor or harness. (3) Compare TDC1 and TDC2 signals side-by-side on a dual-trace scope — if TDC1 is clean and TDC2 is ragged, the problem is isolated to sensor 2 (most cases); if both are ragged, you're looking at a shared ground or 5V reference fault upstream. (4) Replace the TDC2 sensor ($45-85 aftermarket) and the valve cover gasket together if the gasket shows any weeping. The expensive misdiagnosis caveat: don't chase P1366 as a cam-timing problem unless you also see P0341/P0344 or knock/misfire codes — the ECM will throw cam-position codes if the actual mechanical timing has slipped, and a standalone P1366 is almost always a sensor or harness issue, not a timing-belt or chain problem.

Vehicle-specific patterns: 2005-2014 Acura TL/MDX/RL with the J35 V6 throws P1366 in the same VCG-leak scenarios as P1361, often as a paired code (P1361 + P1366 together = both connectors oil-fouled, which is the smoking gun for a leaking valve cover). 2003-2008 Acura TL (J32) shows the same architecture. 2007-2014 Acura RDX with the J35 picks up the same failure mode. Honda Odyssey/Pilot/Accord V6 (J35 sister engine) shares the sensor and the gasket-leak root cause across all VCM and non-VCM trims — a P1366 on a Pilot diagnoses identically to a P1366 on an MDX. Estimated repair: $80 (sensor only DIY) to $450 (sensor + VCG + plenum R&R).