P3402

P3402 means the ECM detects an open circuit on the cylinder-1 deactivation/intake-valve-control solenoid — no current is flowing through the solenoid coil when the driver commands the activation pulse. Cheapest-first ladder: ohm the solenoid across the two harness pins — healthy reading is 8 to 15 ohms cold, infinity means an internally-open coil and condemns the solenoid for $40 to $120 OEM. Inspect the connector at the solenoid for oil contamination (Hemi MDS connectors sit in a low spot on the valley plate and collect oil mist that wicks into the pins and corrodes the contacts) and at the ECM end for backed-out terminals; a single backed-out pin reads as a full open circuit. Backprobe the harness with the ignition on, engine off, and check for B+ on one pin and the ECM's ground-side switching on the other — no power means a blown driver or chafed harness, no ground means an ECM driver failure or harness break. Scan live data for commanded solenoid state vs actual current — the ECM should command 0.5 to 1.5A; if commanded but not measured, the open is real. The expensive misdiagnosis: Chrysler 5.7/6.4 Hemi MDS lifters are the actual problem on 80% of P3400-P3424 codes but P3402 specifically is one of the few that's almost always electrical, not mechanical — a circuit-open code points to wiring or solenoid, and replacing a lifter on a true P3402 misses the actual fault.

Vehicle-specific patterns: Chrysler 5.7L Hemi (RAM 1500 2009-current, Charger/Challenger R/T 2005-current, Grand Cherokee, Durango, 300C) is the most-Googled P3402 vehicle — the MDS solenoid connectors live under the intake plenum and the oil-pan-side harness chafes against the valley-plate edge on high-mileage trucks, so a P3402 on a 150k+ Hemi often resolves to a $0 harness repair, not a solenoid. 6.4L Hemi SRT (392 Charger/Challenger, Grand Cherokee SRT, Durango SRT) shares the same harness routing and chafing failure. GM AFM 5.3L L83 (Silverado/Tahoe/Suburban 2014+), 6.0L (Avalanche/Yukon XL), and 6.2L L86/L87 (Silverado/Sierra/Tahoe/Yukon 2014+) routes the AFM solenoid harness through the lifter-oil-manifold (LOM) assembly under the intake, and a damaged LOM gasket lets oil into the connector and creates an intermittent open circuit. Ford 5.0L Coyote VCT-i (Mustang GT, F150) sets a similar circuit code when the VCT solenoid screen clogs and the ECM's driver shuts down to protect itself — pull the solenoid, clean the screen, reinstall, often $0 in parts. Honda VCM J35 V6 (Pilot, Odyssey, Ridgeline, Accord V6) typically uses rocker-arm-oil-control-solenoid (ROCV) hardware and an open circuit there reads as a P3402-equivalent; common shop fix is the VCM disable harness at ~$120. Estimated repair: $0 (harness repair) to $400 (solenoid + labor).