Contour Enthusiasts Group Archives Forums Modifications Transaxle CD4E repair saga.....

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.

Using your OBD-II software, are you able to monitor the Vehile Speed Sensor (VSS)? This might be your problem, just a thought.

One other thing that comes to mind, as a possible cause is the Turbine Speed Sensor, located on the pump. I have read of simialar problems being resolved by replacing that.

As for the EPC solenoid being cut off after a fault is logged, that is just the PCM going into Failsafe Mode for the transaxle functions. IIRC, and I probably don't, the line pressure is held at 90 PSI when operating in failsafe. Hince the reason you can squell your tires, during those times.

Anyway, welcome aboard and keep us updated on your progress.

If you plan on replacing the solonoid pack, go to www.bulkpart.com

They can be had as low as 135 dollars depending on your year.......

I'd replace the following parts in this order, if it dosen't cure your problem then you would need to rebuild. In the case of a rebuild, these parts would still be useful and desireable to replace.....


Shift Correction Kit
TSS
VSS
Solonoid Pack
Rebuild including new converter.....

If you had slipping occur, then I'd say more clutch pack, damage, pump, etc. If you have shifting problems, then more solonoid pack, tss, vss, etc. I'd get this fixed soon, the longer this goes on the chance of blowing pump seal, converter, etc.

Thanks guys.
I'll keep all that in mind.
I have monitored the VSS signal and it looks very clean and steady.
I'm tapping the TSS this wekend and will monitor for a few driving cycles.
Plus I have this guys used solenoid pack to compare as well.

I should also add that I ran the full set of stall tests and all the pressures passed with flying colors. I have a transducer plugged in the line pressure tap and have been graphing it on my laptop, it looks very good during steady driving and shifts as well. I'm hoping my hunch that the problem lies with shift control is correct.

I've got to bring this problem to a close within a couple of weeks. You see, I liked the Mystique I bought for my daughter so much, that I started shoping for myself and landed a 98.5 Contour SVT off of ebay for $430.00 !!!
Now it's missing wheels, exhaust system, body kit and headlights but I'm very exited about resurrecting this car.
I'll start posting soon in another forum on this one.

Thanks again,
Greg

Well, I tapped the turbine speed sensor tonight. The signal looks very clean and my tekscope displayed a nice sharp sawtooth type waveform. I got about 51hz signal at idle, 133hz at 2000 rpm, 204hz at 3000 rpm, and 263hz at 4000 rpm. I guess that means the sensor sees 4 teeth or pulses for every shaft revolution. (I assume this is tied direct to the motor)
Anyway, it's on to the solenoid pack this weekend. I'll try and wrap this up by early next week.
Greg

what about the shift sensor?

Got a new on just in case for 34 bucks. But it ohmed out very close to the old one and made no difference. I have $896.00 for the car, $37.00 for the Transgo kit, and $34.00 in the TR (shift) sensor so far. I am on a shoestring budget here so I'm reaching hard. My "used" solenoid pack will be waiting on me when I get home tonight. Keep your fingers crossed.
Thanks, Greg

Ok All, Here�??s where I�??m at. And let me say, I�??m about ready to jerk this thing out and just tear it down. I would have already except that the darn thing passes the line pressure tests with flying colors and the rare times it does get into 3rd and 4th gear, it�??s solid as a rock. That makes me believe the bands, drums, and pump are in good shape. Let me recap what I�??ve done:

>Pulled the valve body, stripped down completely, carefully installed the Transgo SK CD4E Jr kit. Very slightly honed each accumulator bore, checked pistons by hand and found that honing definitely reduced friction in each. (I only polished, I�??m sure I didn�??t enlarge the bores to the point of causing excessive bypass)
>Replaced the TR (Transmission Range) sensor, (checked old and new, both passed resistance check)

>O-scoped both VSS and TSS signals while driving. Both outputs produce nice high amplitude waveforms and are comparable to what any hall effect sensor is supposed to produce.

>Pulled the solenoid pack again, tore down, carefully cleaned/reassembled. (I checked each solenoid for operation while disassembled and after assembly, all worked as designed. Also checked temperature sensor (thermistor) reads about 30K ohms at room temp and drops to below 5K rapidly with hair dryer blowing on it.) I also had a �??96 model solenoid pack for comparisons while doing this, it checks out the same other that a redesign of the electrical harness connector.

> I have Alex Peper�??s TRICAN OBD II enhanced code reader (I love it!) but the only codes I get from this Mystique are �??3rd gear wrong ratio�?� and �??4th gear wrong ratio�?� kinda makes you want to scream DUH!!!!!

> I still have 5 LED�??s hooked up to the harness at the top of transaxle connector monitoring the ECM commands to the 5 solenoids. All signals agree with Ford�??s shift tables at all speeds/driving conditions. (I just can�??t get 3rd gear when it�??s commanded, nor 4th)

I�??m asking for advise here, and I also want to specify a couple of questions:

1) Is there a way to hook up to a port with the valve body off and manually actuate/leak check the 3rd gear band actuator?
2) Is there information available that tells what function each spool piece in the valve body does so I can disassemble again and maybe check for wear specifically on those spools?
3) Does the zeetec motor have a rev limiter when in Park or Neutral? Because when I rev up in N or P, it hits 4000 RPM and bounces there at 3800 to 4000 as if electronically limited.

Thanks for reading and for any advise/answers you can offer.
Greg

Well I looked up the DTC codes and here is what I found...

Intermittent harness continuity.
Damaged Transmission Range (TR) Sensor.
Damaged shift solenoid.
Worn friction elements.
Enter Key On Engine Off Continuous Monitor Diagnostic Test Mode (DTM) . See: Displaying and Reading Trouble Codes (Includes Quick Tests)\Quick Test Appendix (Detailed Testing Instructions)
Observe Analog Volt/Ohm Meter (VOM) or STAR Tester LED for an indication of a fault while performing the following:
Wiggle, shake or bend a small section of the Powertrain Control Module (PCM) vehicle harness while working toward the dash panel, PCM and transmission connectors.
Is a fault indicated?

If you can't find a electrical problems...it may be time to replace the clutches/steel bands. One idea I have (just an idea mind you) is PERHAPS you can add a friction modifier to your fluid and see if it makes any difference. If you see an improvment I would say it's time to replce the clutches/steels -- rebuild time..... One key is your line pressure...since you stated it is good, this would indicate to me the valve body is in good shape......

If you switch the overdrive button off, does anything different happen?

Regards,
Bob

Thanks for checking in on me Bob.
When I cancel overdrive, I get engine braking as I should but in 2nd gear since a shift to 3rd rarely ever takes place. When I leave overdrive active, (Light off), I can run the car up to 60 mph or so, (5000-6000 rpm) then let off and the car coasts as designed (TCC unlocks). While coasting down I can tap the OD cancel button say at 50 mph. The shift solenoid signals set properly, (as observed on my monitor LED's), I will feel 3rd gear pull in, then within 2 seconds, 2nd gear locks in with heavy engine braking of course.
***I also want to note this: In a nominal acceleration test, say going from stop to a steady and holding 45mph, 1st then 2nd gear shift smooth and normally. Then as you hold at 45mph, you can feel an occasional (say every 3 to 10 seconds) forward pull or bump from the drive train and observe a slight "dip" in RPM's which I believe is the third gear shift attempting to engage. I JUST CANT FIGURE OUT WHY IT WON'T GO ON AND HAPPEN !!!
Don't mean to sound frustrated, but I really am.
Any more thoughts?
Thanks,
Greg