OBD Operation Summary for 6.7L Diesel - MotorCraftService.com

Transmission OutputsShift Solenoids6R140 has 5 shift solenoids:1. SSA – a Variable Force Solenoid (VFS) that controls CB1234 (a brake clutch, grounds an element tothe case, that is on in 1 st , 2 nd , 3 rd and 4 th gear)2. SSB – a VFS that controls C35R (a rotating clutch on in 3 rd , 5 th and Reverse)3. SSC – a VFS that controls CB26 (a brake clutch on in 2 nd and 6 th gear)4. SSD – a VFS that controls CBLR (a brake clutch on in 1 st gear with engine braking and Reverse)5. SSE – a VFS that controls C456 (a rotating clutch on in 4 th , 5 th and 6 th gear)Output circuits are checked for opens, short to ground and short to power faults (codes listed in that order) by the"smart driver" (see ADLER below) that controls the solenoids (SSA P0750, P0973, P0974; SSB P0755, P0976,P0977; SSC P0760, P0979, P0980; SSD P0765, P0982, P0983; SSE P0770, P0985, P0986).The shift solenoids are also functional tested for stuck on and stuck off failures. This is determined by vehicleinputs such as gear command, and achieved gear (based on turbine and output speed). In general the shiftsolenoid malfunction codes actually cover the entire clutch system (solenoid, valves, seals and the clutch itselfsince using ratio there is no way to isolate the solenoid from the rest of the clutch system)For SSA thru SSE Diagnostics will isolate the fault into clutch functionally (non-electrical) failed off (SSA P0751,SSB P0756, SSC P0761, SSD P0766. SSE P0771) and clutch functionally failed on (SSA: P0752, SSB: P0757,SSC: P0762, SSD: P0767, SSE: P0772).Torque Converter ClutchThe Torque Converter Clutch (TCC) solenoid is a Variable Force Solenoid. TCC solenoid circuit is checkedelectrically for open, short to ground and short to power circuit faults internally by the "smart driver" that controls thesolenoids (P0740, P0742, P0744).The TCC solenoid is checked functionally for stuck off faults by evaluating torque converter slip under steady stateconditions when the torque converter is fully applied. If the slip exceeds the malfunction thresholds when the TCCis commanded on, a TCC malfunction is indicated (P0741).The TCC solenoid is monitored functionally for stuck on faults (P2758) by monitoring for lack of clutch slip when theTCC is commanded off, but this code is non-MIL because while a stuck on TCC solenoid may cause driveabilitycomplaints and/or cause engine stalls it does not impact emissions or fuel economy.Electronic Pressure ControlThe EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid ismonitored for open, short to ground or short to power faults by the "smart driver" that controls the solenoid. If ashort to ground (low pressure) is detected, a high side switch will be opened. This switch removes power from all 7VFSs, providing Park, Reverse, Neutral, and 5M (in all forward ranges) with maximum line pressure based onmanual lever position. This solenoid is tested for open (P0960), short to ground (P0962), and short to power(P0963) malfunctions.Transmission Solenoid Power Control (TSPC)6F140 PCM or TCM has a internal high side switch called TSPC that can be used to remove power from all 7solenoids simultaneously. If the high side switch is opened, all 7 solenoids will be electrically off, providing Park,Reverse, Neutral, and 5M (in all forward ranges) with maximum line pressure based on manual lever position.FORD MOTOR COMPANY REVISION DATE: FEBRUARY 9, 2012 09.01.00.02-PAGE 152 OF 157