P2720

P2720 means the TCM has detected an open circuit on Pressure Control Solenoid F — no current flow when the solenoid is being commanded on. The TCM measures coil current continuously during PWM drive (Pressure Control Solenoids are typically PWM'd at 100-300 Hz to produce a variable hydraulic output), and any time commanded current is non-zero but measured current stays at zero, an open-circuit code fires. Cheapest-first ladder: pull the connector at the trans case (or the external solenoid pack on platforms that have one) and ohm the PCS coil — healthy reading is 8-30 ohms cold depending on application (ZF 8HP solenoids run on the lower end around 3-6 ohms; GM 6L80 PCS values are 8-12 ohms; Aisin AS69RC solenoids 5-10 ohms). An open coil reads OL on the meter and condemns the solenoid; an in-spec coil reading means the wiring or the TCM driver is the suspect, which is a back-probe job at the TCM harness side. Drive current under PWM should hit 0.5-1.5 A on a scope when the solenoid is commanded high; intermittent open with full coil resistance often points to a corroded internal pass-through connector at the case. Caveat: an external pressure-control solenoid swap is a $150-400 part-plus-labor job; an internal valve-body solenoid means dropping the pan ($400+ in labor before parts) and a mechatronic-style integrated unit (ZF 8HP) means a complete mechatronic rebuild at $2,000+. Confirm internal vs external BEFORE writing the estimate.

Vehicle-specific patterns: 2007-2014 GM 6L80/6L90 (Silverado, Tahoe, Yukon, Camaro) is the most common P2720 ticket in North American shops — the 6L80 uses multiple PCS solenoids labeled A through F mounted on the valve body inside the pan, integrated into the TEHCM assembly; when one fails, GM's service procedure is typically a TEHCM replacement at $600-900 part plus labor. 2011+ Ford 6R80 similarly uses multiple PCS solenoids on its lead-frame and throws P2720 alongside solenoid-pack codes when the internal harness corrodes. 2009+ ZF 8HP electro-hydraulic mechatronic module integrates all pressure-control solenoids into a single sealed unit — P2720 on a ZF 8HP almost always means a mechatronic rebuild ($1,800-2,800) rather than a single-solenoid swap. 2013+ Aisin AS69RC behind the Cummins 6.7L uses externally-serviceable solenoids on the valve body — pan-drop is required but individual replacement is feasible. Estimated repair: $250 to $3,200.