Some 2011 Mercury Grand Marquis vehicles equipped with a 4R75E transmission may exhibit an un-commanded torque converter clutch (TCC) apply or TCC partial apply immediately after the 1-2 shift.
This may result in the perception that the vehicle lacks power or the transmission is up-shifting too early. DTC P1742 may be stored in the PCM. In some vehicles, while operating in manual 2nd gear and when coming to a stop, the vehicle may experience a loss of rpm.
1. Install IDS scan tool.
2. Road test the vehicle and monitor (TCC%) solenoid command state – duty cycle and (TC SLIP ACT) torque converter clutch slippage – rpm, while in 2nd, 3rd or 4th gear with a TCC% reading 0.
a. If TCC% = 0 and TC SLIP ACT = less than 20 rpm, then inspect the number 7 check ball in the main control valve body for damage. Replace as needed. This procedure is performed in 2nd gear auto (not manual 2nd). Monitor TC SLIP ACT after the PCM commands 2nd gear and before the vehicle speed sensor (VSS) reads 35 mph.
b. If you receive any other reading, this bulletin does not apply. Refer to the workshop manual section 307-01A for normal diagnostics.
Note that it is normal for the PCM to command 4th gear at speeds as low as 19 mph with light acceleration when the throttle position is less than 20%.
P/N .................................... PART
EOAZ-7E195-B................... Check ball
1L3Z-7C155-AA.................. Gasket, valve body upper
1W7Z-7D100-AB................ Gasket, valve body lower
XT-10-QLV.......................... Motorcraft MERCON LV automatic transmission fluid
