O/T, but ford- Trans

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Scott Tanner

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Greetings,



can l1tech or anyone with ford tranny experience shed some light on this?



I'm batting squirrel nuts on Ford pasenger car trannies..



I have a 2007 Mercury fusion (Milan) with the 5 speed FRN5 auto. This car has been nice for over 100,000 miles, but the trans is acting up now. The 3-2 downshift is harsh, and now throws the wrench light. The dealer reprogrammed the PCM, and they did a fluid swapout. Supposedly, it still has the shudder. Below is a list of observances that the cars has presented. I gave this list to the dealer..



Mercury Milan



In for Transmission shifting issue

History



Last 4-5 months, the original battery has been real weak. In the last month and a half, the car has had a dead battery on a few occasions. Three weeks ago and new battery was installed. The trans issue started prior to the battery replacement. I was postulating that the battery was causing the trans module to lose its programming or something. New battery did not fix.



If I remove battery cable, it would run fine for a while, but the 2-3 upshift was a little rough, and the 3-2 downshift was harsh.



The wrench on the dash came on, and the trans would shudder violently when placed from park to reverse, acting like it was put into two gears at the same time.



For 3 weeks, the trans worked fine, as long as I dont have it in gear when I slow to less than 25 mph. I would shift into neutral when approaching a stop. If I did not do this, the trans would go directly to 1st and the engine revs would go to 2500-3000 rpms. Once this happens, I would have to shut the engine off and restart, which would sometime work, but usually I would have to disconnect the battery for 5 minutes.

.

While driving the car to your dealership, the car started acting up again, not knowing what gear to be in, and/or the convertor was locking and unlocking. It was acting like a sensor was wigging out, causing bad data to be supplied to the trans module or something. I would guess that the learning part of the module would be compromised when given bad data to interpret.



The trans has not has a fluid flush, and definitely needs one.



For at least 3 years, the trans would occasionally, during the 1-2 upshift, rev to 2000-2500 rpm before shifting when cold, but not all of the time.





Other issues include the secondary air pump system, and the cooling system.



I was getting a P0128, coolant not up to temp. A thermostat and coolant temp sensor change seems to have fixed that.



Codes P0410 and P0491 came up, secondary air pump system, I hotwired the pump at the relay box, the pump sounded like the brushed were bad, as it sounded like intermittent operation. Upon removal of one of the hoses, the pump was full of water. Research provided info of the control valve not closing letting in condensation from the exhaust. The valve was removed, and it tested OK. The vacuum lines were checked, and found a hole in side of line due to rubbing on the engine. I repaired line, codes show that ODB-II is still pending. I do not know if the vacuum line issue affected the other issues with the car.





The CEL codes have been fixed. I am wondering if the weak battery started all of this. I read a thread on the forum where that owner had a similar issue, which was fixed with a fresh battery.



I talked to an independent trans shop in town that has a very good reputation, and they suggested adding a friction modifier to the fluid to help the shifting. It seems that solenoids are sticking and causing the trans to try to engage two gears at once.. I am going to try this, because I have nothing to lose. I can get a used trans for $400, but am concerned that an issue external to the trans is causing this.



Any ideas? Thanks in advance for any replies.

 
With those kind of issues I am amazed that it isnt throwing a P07xx code for a trans fault but that would make things easy wouldn't it. With no codes present the first thing I would suspect is the servo bore for the band that gets activated in 2nd and 4th. The bore wears and causes all sorts of shifting issues without setting any codes. Unfortunately you have to tear the trans down to inspect this. Have actually seen brand new rebuilds with this problem. There is a company out there that makes a special tool to bore out the bore and put in a bushing to make things right again but unless you are a trans rebuilder it isn't one of those things you are gonna go out and buy.



A TPS issue could also cause your symptons or a worn out throttle body, you would actually have to replace te whole throttle body for either one of these issues.



Another issue potentially could be the mass airflow meter. These have alot of influence on how the trans shifts.
 
Thanks for the reply...



It did throw a code, but I don't have it in front of me right now.. I picked the car up from the dealer, paid the $425 for diagnostics and fluid change, and drove up the road 1/4 mile, when I noticed the speedometer needle going haywire. I did a U-turn and headed back to the dealer. upon approaching the traffic signal, the car died and trans shuddered, along with the speedo going nuts. The wrench light flashed once, i believe. They have it again. I told them that I'm thinking that the trans or computer is receiving bad input data from the sensors. They said they checked all that. My response to that was that sensors are flaky and issues are often intermittent. We'll see.. I'll get you the code as soon as i see the paperwork again..



:fire::fire::fire:
 
The dealer want to put in a new trans, wich they re not going to get the chance to do, as I'll put a used one in (my brother works in a used parts salvage yard). My concern is that something external to the trans is causing this, and the repacement trans will see the same fate..







No more auto trans ford cars for me Next one will be a stick shift. My last ford car, a 96 Sable, had trans issues too.

 
l1tech, the code thrown was P0744- torque converter. I still think there is something goofy going on with the inputs. Garbage in, Garbage out.. Another mechanic friend I know postulated if the input and output speed sensors don't jive, due to a faulty signal, it could cause the TCM to wig out..



I found this document online,



Mazda FNR5 (FWD) Transmission

FNR5 is mechanically similar to the FN transmission; with an add-on gear set increasing it from a four-speed to a

five-speed transmission.

Transmission Inputs

The Transmission Range Sensor (TRS) provides a single analog input to the TCM. This input voltage is monitored

for mis-adjustment (P0706), opens (P0708) and shorts (P0707).

The Turbine Shaft Speed (TSS) sensor is a variable reluctance sensor; with rationality check for opens and shorts

(P0715).

Intermediate Shaft Speed (ISS) and Output Shaft Speed (OSS) sensors are analog inputs that are checked for

rationality. If the engine rpm is above the torque converter stall speed or one of the two speed sensors has

sufficient signal, it can be inferred that the vehicle must be moving. If there is insufficient output from the ISS

sensor, a malfunction is indicated (P0791). If there is insufficient output from the OSS sensor, or a disconnected

sensor a malfunction is indicated (P0720).

Transmission Fluid Temperature Sensor is checked for stuck (P0711), Low input or Short (P0712) and High input

or open (P0713).

Transmission Outputs

Shift Solenoids

The three On/Off Shift Solenoids (SSD, SSE, SSF) output circuits are checked for opens and shorts by the TCM

by monitoring the status of a feedback circuit from the output driver (P0768, P0773, P2709 respectively). The shift

solenoids are functionally (mechanically) checked by means of a comprehensive malfunction pattern test. This

monitor examines gear ratios to determine if a shift solenoid failure is stuck on (P0767, P0772, P2708) or stuck off

(P0766, P0771, P2707 respectively).

The four Duty Cycle Solenoids (SSA, SSB, SSC, PCB) are functionally checked by means of comprehensive

malfunction patterns for stuck on (P0752, P0757, P0762, and P0777), for stuck off (P0751, P0756, P0761, no

code for PCB), and have a continuity check for open or shorted (P0753, P0758, P0763, P0778).

Torque Converter Clutch

Multiple solenoids control the TCC in the FNR5 transmission. Electrical checks for all shift solenoids are performed

as indicated above. The TCC is checked functionally by evaluating torque converter slip under steady state

conditions when the torque converter is fully applied. If the slip exceeds the malfunction thresholds when the TCC

is commanded on, a TCC malfunction is indicated (P0741). If slip is below an open converter threshold when the

TCC is commanded off, a TCC malfunction is indicated through the shift solenoid functional test (P0742). The TCC

also has a check for intermittent slip detection (P0744).

Pressure Control Solenoid

The Pressure Control Solenoid A is a linear solenoid. This solenoid has a continuity check for shorts and opens

(P0745).

FORD MOTOR COMPANY REVISION DATE: NOVEMBER 12, 2007 PAGE 153 OF 159

Transmission Control Module (TCM)

Power Supply

If the TCM input power voltage is low a code is set (P0882).

CAN Communications

The TCM receives information from the ECM via the high speed CAN connection. If the CAN link or network fails

the TCM no longer has engine information available. The TCM will store a U0073 fault code if the CAN Bus is off or

a U0100 fault code if the TCM stops receiving CAN messages from the ECM.
 
Your friend is right, if the sensors aren't doing their job then all sorts of strange things can happen. Over the internet there just isn't any help that I can give you on this one and unless you can plug into this with a factory scan tool you aren't going to be able to figure it out unless you happen to guess correctly.
 
Update:







The code thrown at the dealer was P0744- torque converter. I still think there is something goofy going on with the inputs. Garbage in, Garbage out.. Another mechanic friend I know postulated if the input and output speed sensors don't jive, due to a faulty signal, it could cause the TCM to wig out..







I picked it up from the dealer, and the speedo was not working right. It would jump around and evendently make the tranny shift wierd, and TC would slip and lock up again. It did not do this prior to the TCM reprogram.







I limped it up to a notable trans shop in town that has a good rep, and this morning the owner hooked up a bluepoint code scanner to it and took it for a ride. The P0744 was not on there, but a P0720 was- OSS (output shaft sensor), thus kinda supporting my external fubar sensor theory. He wanted me to drive it for a while, to get more info to scan. BTW, the car drove fine for him, which is just my luck. I took it and drove to work the long way this AM for about 20 miles, and the car drove flawlessly.. I don't know if he "loosened something" or it just decided not to throw a fit today. His scanner did not show P0744, BTW





 
Last edited by a moderator:
Update 2



Drove it from work back up to the trans shop after a day at work, car misbehaved again. The speedo did not work again, but when it did decide to work, the trans worked fine. This morning, the shop connected an analyzer to it and drove to retrieve the codes. Their prognosis with a high level of confidence is a intermittent Output speed sensor and/or wiring. I gave them the go ahead to perform their level 1 diagnostics, which involves intercepting the various sensors signals. This is my kind of diagnosis-



 
On another forum a member stated that the speed sensor must be fixed before a complete diagnostic can be performed, I responded:



I agree 100%... Like I said, garbage in, garbage out... I hope to hear from the trans shop today on the car. I am somewhat dissapointed at the dealer, as they wouldn't dive into the true cause of the issue, but rather change parts. Hell, I can change parts... It's like trading in your car because the ash tray is full.... I can understand the dealer's stance, but how many customers have they raked over the coals buy doing schiitt (FE-ism, btw) like this to customers? You betcha I going to complain to Ford on this. (not that it'll make a difference)... I do controls and automation for a living, and if I did this, I'd be out of a job. When diagnosing issues, you have to do a root cause analysis to get the source. Anything else is a symtom. In this case, disconnecting the battery for an hour and having the trans work fine was the first clue. With a bad input, the TCM learns wrong and then we're back to square one. It's a shame the dealer could not process this. Another thing, the speedo appeared to work fine until Ford reprogrammed the TCM. I pointed out that it worked when I brought it in. If I complain to Ford, maybe I'll get a free Ford coffee mug (fat chance) or something...



off the soap box...







I'll repost when I get more info, so others can benefit from this buffoonery..

 
Well, I called and it is ready to be picked up... A new OSS (output Speed Sensor) and it shifts fine, according to the shop. The damage? $415.00 I gave the dealership $425.. In a way, the dealer doing something to make the speedo go ape-schitt kinda pointed out the problem. Too bad they couldn't fix their own products. Makes you wonder. Maybe there are no bad Ford transmissions... just bad service dept's. Grrr.
 

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