P0782

P0782 is the 2-3 shift malfunction — TCM commanded a 2-3 upshift, didn't see the input/output ratio land at the third-gear target (around 1.0:1 on a direct-drive third in a 4-speed, around 1.0-1.1:1 on most 6-speeds), and set the code. The 2-3 shift is historically one of the highest-stress shifts in any transmission because it's when full torque-converter lockup gets armed on many platforms and when the 3-4 clutch (or its equivalent) takes a heavy load. Cheapest-first ladder: (1) Fluid level and condition first — every time, no exceptions. (2) Live-data scan during a road test: command-gear vs. actual-ratio during the 2-3 shift; if the ratio crosses second-gear value, hangs in a flare (RPM bump as torque drops momentarily), then lands at third late, that's a slipping 3-4 clutch or the 2-3 shift valve sticking — both repairable, but at different price points. (3) Ohm the 2-3 shift solenoid (or the SS2/SS3 solenoid set, depending on platform) — 8-30 ohms typical; off-spec is a solenoid swap, on-spec moves suspect to the valve body or the clutch pack. (4) Drop the pan and inspect the magnet — black flake or paper-towel-thin friction material in the pan is 3-4 clutch debris and a rebuild is the only fix. The expensive-misdiagnosis caveat: a slipping 3-4 clutch generates heat fast — every additional 1,000 miles of driving past the first P0782 typically degrades the clutch-pack friction surface another 10-20%, which is why a $300 valve-body fix becomes a $2,800 rebuild if the owner ignores it for two months.

Vehicle-specific patterns: 1995-2014 GM 4L60E throws P0782 from 3-4 clutch pack burn — this is THE textbook 4L60E failure mode in pickups and SUVs that tow above their rating; the clutch pack overheats, the friction material falls off the steels, and the 2-3 shift goes soft then disappears. Rebuild with upgraded 3-4 clutch pack (Sonnax/Alto/Raybestos) is $1,800-3,200. 1995-2008 Ford 4R70W/4R75W throws P0782 from the direct clutch wearing or the forward-clutch piston seal failing; rebuild $1,800-2,800. 2003-2012 Chrysler 545RFE throws P0782 from the OD/2C clutch wearing, common around 130-180k miles. 2007-present BMW 6HP/8HP (ZF) throws P0782 from a clogged valve body or mechatronic problem, typically resolved with valve-body replacement at $1,500-2,800 plus fluid. Estimated repair: $400 (solenoid) to $3,200 (rebuild with upgraded 3-4 pack).