I??ve been reading the posts here for about 2 months now as I have worked once or twice a week on the 1998 2.0L 4cyl automatic CD4E Mercury Mystique that I purchased for my daughter. I thought I should contribute by posting my progress.
I??ll start with the symptoms: about 10% of the time, the car performs flawlessly. The other 80 it decides it will not go further than 2nd gear. After driving a few miles at 4000 RPM and 40 miles per hour, you will usually get an abrupt shift to 3rd as the PCM issues a transmission code and the ??OD OFF? light begins to flash. Yet sometimes even with the fault code setting, 1st and 2nd gear is all you will get.
I began by taking the valve body out. I carefully polished the bores of the three accumulators, installed the SK CD4E Jr kit from Transgo, then surgically cleaned and re-assembled it all with new separator plate gaskets. (I did nothing with the solenoid pack this time, just wiped clean and reinstalled)
I got no change! Now the first few miles seemed promising, but within a half hour of driving time, the problem was still there.
I purchased some OBD II software and an interface for my laptop to read the ??enhanced? codes, (the generic off the shelf scanners will not pick up most transaxle codes) The whole OBD II experience is another story itself !!!
It keeps setting two codes: ??3rd gear wrong ratio? and ??4th gear wrong ratio? DUHH !!!!
Apparently, the PCM is calling for 3rd and then 4th gear at times and realizes that due to input vs. output rotation RPM, it??s not getting it??s proper gear/s. Don??t you love it when a computer can tell you what you already know!
Well, Sunday night (6/13/04), I took the pan off again and inspected the solenoid pack. You have 5 solenoids in the CD4E, SS1 and SS2 are ON/OFF valves that schedule gears 1,2,3,4. There is a 2-3 shift scheduling solenoid (2-3 SSC), from what I understand its actually a stroke-able control valve that picks the right time and how abrupt the up or down shift goes from 3rd gear. The torque converter control (TCC) (Ford calls it a Modulated Lockup Solenoid MLUS), it??s a little valve that looks like SS1 and SS2 but is pulsed on and off (PWM) to control when and how much the torque converter lock up clutch is applied. Then last but not least, the Electronic Pressure Control (EPC) solenoid. (Looks and works just like 2-3 SSC) This one makes me laugh a little. See, when the PCM decides to kill all the signals to the transaxle due to certain fault codes setting, which has happened to me many times, the EPC gets cut off as well. Driving this little 140hp 4 banger with no electronic pressure control is a little squirrelly to say the least. In moderate acceleration, 1st to 2nd gear brings a squawk from the front tires that I used to have to try really hard at to get out of my ??69 fastback in high school. It??s got to be hard on the running gears but it sure does bring a smile when stander-bys look at the car with that ??confused? daze on there face! Ok, enough playing and info on solenoids.
Ford says these are not service-able, but at nearly $300.00 apiece, I??m giving it a try anyway. I cleaned and inspected the solenoid assembly. Was able to disassemble the seats SS1 through SS3 and they seemed a little sticky. Without de-crimping some very brittle looking tabs, you cant get at the cores of SS1 through SS3 or even start on the two stroker valves. So I put it all back together. Amazingly, the tranny was flawless for two warm up cycles and over 20 miles of driving. Then the same old crap started again yesterday. And no it??s not dirt. The fluid has been very clean from start.
I did get some LED??s hooked up to each of the 5 inputs from the PCM, I have monitored the signals, (carefully while driving), and according to the shift schedules in the Ford manuals the PCM is doing as designed.
I plan on pulling the pack again this week. I have a guy I met at a tranny shop that has a spare used pack he says he will let me try. I also plan on de-crimping the little monster and inspecting/polishing the cores, seats and guides to see if sticky valves may in fact be the problem.
I know this is long and drawn out, but if anyone else gets to this point, you??ll know how I feel. Please add/respond with any comments or advise you may have.
