P2718

P2718 is the high-side complement to P2717 — Pressure Control Solenoid D control circuit HIGH, meaning the TCM driver is seeing the solenoid command line pulled to battery voltage (or floating high) when it should be PWM-cycling under command. The fault modes are: the solenoid coil is internally open (the winding has broken and the driver sees no load), the harness wire from the TCM to the solenoid is open (broken or unplugged at the case connector or at a splice), the harness wire is shorted to a 12V power source (uncommon but possible if a chafe puts the PCS line against a battery feed in the engine bay), or the TCM driver has failed open on that channel. A healthy PCS-D coil reads 8-30 ohms; an open coil reads infinite resistance on a meter. Cheapest-first ladder: with the harness reconnected, scope or DVOM the TCM driver pin during a commanded lockup — a healthy driver pulses 0V to 12V, an open-circuit fault sits at 12V (pulled high by the internal pull-up in the driver IC) and never drops; disconnect the harness at the trans case connector and measure resistance through the harness side from the connector pin back to the TCM pin (should be near 0 ohms — a high reading or open means a broken harness wire); pull the trans pan and inspect the internal lead-frame for cracks at the bend points and the connector for pin-fret; check coil resistance directly at the solenoid terminals after removing it (infinite resistance confirms open coil); inspect the case-connector pass-through for fluid intrusion that corroded a pin off the lead-frame. Before condemning a complete solenoid pack on a P2718, ALWAYS isolate whether the open is in the coil, the lead-frame, or the external harness — a broken external harness wire at the case-connector pin is a 30-minute repair on a Ford 6R80, while a broken lead-frame inside the pan is a full solenoid-pack or valve-body service for many hours of labor.

Vehicle-specific patterns: 2011-2017 Ford F-150/Expedition/Mustang 6R80 throws P2718 from PCS coil winding failure (open-circuit) and from lead-frame fracture at the bend over the valve body — same population that throws P2717 on the short-side, just the opposite failure mode on the same component family. 2013-2018 Ram 2500/3500 Aisin AS69RC throws P2718 from internal harness break in the trans pan and from solenoid coil aging; AS69RC solenoid replacement is usually done as a full pack rather than individual solenoids because labor dominates. 2008-2014 GM 6L80/6L90 throws P2718 from PCS coil open-circuit failure and from case-connector pin-fret on high-mileage trucks — the pin-fret signature is intermittent codes (P2718 sets, clears, resets after a few drive cycles) that progress to hard-fault. 2009-2014 Chrysler 545RFE/65RFE throws P2718 from solenoid pack coil failure. 2007-2013 BMW ZF6HP/ZF8HP throws P2718 from mechatronic-internal solenoid coil failure, requiring mechatronic replacement or rebuild. Estimated repair: $250 to $2,200.