Some 2012-14 Ford Edges and Explorers, as well as 2013-14 Ford Taurus and Lincoln MKT models (all with 2.0-liter directed-injected turbocharged engines) may produce a host of drivability issues.
Among the comments you might hear from the customer are that the engine is difficult to start or won't start at all, is down on power, hesitates on acceleration and/or idles poorly.
Ford says the drivability woes will likely be accompanied by an illuminated Check Engine light, with trouble codes P0106, P0128 and/or P0236 logged in the PCM. One likely cause for all these symptoms is a bad signal return splice.
Start the fix by connecting your scanner and checking for trouble codes. If DTC P0128 is the only code logged, check and, if necessary, adjust the coolant level.
Next, grab a wiring schematic and locate the signal return splice (S176 on Edges and Explorers, S113 on Taurus and S112 on MKTs). Once you find it, cut out the bad wiring and replace it with five inches of 18-gauge wire and a couple of crimps from a terminal kit. To complete the repair, backfill the crimps with solder, seal the new splice with heat shrink tubing, clear the code(s), start the engine and verify that the drivability issues have been resolved.