P0342

P0342 means the Bank 1 CMP signal voltage is stuck below the low-threshold limit — the sensor signal is shorted to ground, the sensor is dead with internal short, or the signal wire has chafed against a grounded surface. The engine usually starts and runs because most modern ECMs can synthesize a fallback CMP from the crank signal alone, but you lose sequential injection precision and VVT goes open-loop. Cheapest-first ladder: unplug the CMP connector and key-on, then measure signal wire to ground at the harness side (should read 5V reference floating; if it reads 0V, the wire is shorted to ground upstream). Plug back in and recheck — if voltage now reads 0V, the sensor is internally shorted. Inspect the harness route between sensor and ECM for chafing against the valve cover, EGR pipe, or intake manifold bolts. Check for oil saturation of the connector from a leaking cam-cover gasket — wet electrical contacts read as a short to ground in 90% of cases. Verify 5V reference at the sensor connector (pin varies by platform; check service info) — a failed 5V regulator inside the ECM will pull all three reference circuits down and you will have P0342 alongside throttle and MAP codes.

Vehicle-specific patterns: Honda K-series CMP at high mileage frequently fails low rather than open as the Hall IC degrades — bench-test will show a sensor that produces a stuck-low output instead of clean square waves. Ford 5.4 3V Triton sets P0342 alongside cam-correlation codes when a failed phaser also damages the CMP signal pattern. VW/Audi 2.0T EA888 sees P0342 from oil intrusion into the CMP connector when the cam adjuster gasket leaks (extremely common, gasket is $15). Nissan VQ35DE (Murano, 350Z, Altima) throws P0342 from valve-cover oil leaks soaking the CMP pigtail until the insulation breaks down. Estimated repair: $120 to $580.