Limited Transmission Function Message

[Chrisokau]

Reposting this from another forum.
Hi all, I have a sad tale that from what I read is not uncommon. Just after any advice I can get. My 2012 MC TDCI LX wagon gearbox just got the dreaded "limited transmission function" warning and I lost first, third, fifth and reverse. The local Ford dealership are wanting around $14k to replace the transmission. The car has done around 224k but other than the always a little rough gear changing from 1st to 2nd, it has been a fantastic car for the two years that we have had it. I had the transmission serviced twelve months ago but unsure of the prior service history at this point (I am endeavouring to find that out). Does anyone have any meaningful advice to give? At this stage I am just looking at wrecking it and buying another car. Such a f$&@ing waste!
BTW the Self Test codes that it throws up are: P0715, P0700 and P0797. Also, I have since had different things happen. At one stage the transmission came right after sitting for a few days before reverting within 10km. Then a few days later I went to start it and it went straight to reverse and stalled. Now it's back to the limited functionality. So it seems to me that the problem is electronic!

[11ford11]

contact the guy who serviced it as it may be a faulty/corroded wiring connection at transmission or low oil but more likely failed trans control module which is internal to trans and not sold separately
price from ford wreckers fitted keep in mind it is common failure

[Mondaveo]

Hi Chris. Out of interest, what other forum are you coming from mate? It seems you've made a post in this very forum before, although your new thread here has some new information.

Originally Posted by Chrisokau

the Self Test codes that it throws up are: P0715, P0700 and P0797.

P0715: "Input/Turbine Speed Sensor A Circuit"
P0700: "Transmission Control System TCS Malfunction"
P0797: "Pressure Control Solenoid C Stuck On"

I encountered a malfunction with my TDCi Mondeo that produced P0715, that was due to a faulty electronic sensor in the gearbox. You can read all about my experience here. The problem was resolved by replacement of the sensor at a cost of about $2,500.

I didn't personally experience the other two codes you've listed. Unfortunately, they sound like a lot of things going wrong, which is probably why Ford want to change out your entire transmission. However, I think there's a good chance you've just got just one of the common sensor or module failures and those other codes have just occurred as everything is getting confused.

The symptoms I had were irregular rough or hesitant gear changes in low gears. I only once got the "limited function" message with the loss of all drive. In comparison, manchu had an issue that was resolved by replacement of the transmission control module (TCM), but his experience of the fault featured a lot more "limited function" messages and tow trucks.

To pin it down we'd need to know more about the exact behaviour of the car and when and how often the trouble codes are occurring. How did you come by the codes you've quoted above? If you aren't already, the best way (IMO) is to equip yourself with an OBD reader dongle such that you can record and monitor the car yourself whenever you're driving. (See some relevant discussion here.)

With what you've provided, I have to agree that it seems most likely your issue stems from a failed TCM and most economical repair will be to source a replacement gearbox from a wrecker.

Keep us posted

[Chrisokau]

Thanks for the replies. Sorry, I actually meant to say that I had posted in another thread but I thought it was the wrong one so reposted here with the updates. At the moment I can't risk driving it. If it was to stick itself in reverse at speed it could be disastrous! I just went out and started it and initially it seemed fine again but the transmission limited function message soon came on. I did try changing through the gears and interestingly, when I went to sports mode and tried to change down to first the display showed seven!! When I put it into reverse the rear detection sensor started beeping and wouldn't go off, even in drive, until I put it back to park. I am going to contact a transmission specialist tomorrow but I suspect that a second hand transmission is the only way to go and even then I won't get out of it for under 5 or 6 grand I reckon. In the meantime I bought a 2011 Camry for $5k. At least I know they are reliable. If I can get the Mondeo repaired I'll sell it. Sigh. Never again will I buy a car with a DSG gearbox. BTW, the local Ford dealer have me the codes. Also, the car is definitely not drivable as I can only get 2nd, 4th and 6th and as I said, the fact that at one stage it kept putting itself in reverse immediately upon starting has made me very gun shy!

[Mondaveo]

Originally Posted by Chrisokau

At the moment I can't risk driving it. If it was to stick itself in reverse at speed it could be disastrous!

I don't think that scenario is possible - modern transmissions have an interlock that prevents reverse being selected at speed. Although with my car I found it to be dangerous enough with a bad speed sensor causing balking on 1-2 gear shifts - and I still had all my gears - so fair call.

Originally Posted by Chrisokau

I did try changing through the gears and interestingly, when I went to sports mode and tried to change down to first the display showed seven!!

I've found gear 7 once, the time I had the Transmission Limited Function warning and no drive... I suppose it means that the requested gear is not selectable.

Originally Posted by Chrisokau

When I put it into reverse the rear detection sensor started beeping and wouldn't go off, even in drive, until I put it back to park.

This sounds like normal operation; the proximity sensors come on with reverse and remain on until forward speed increases above a threshold or Park is selected. Did you try the dashboard button to turn them off?

Originally Posted by Chrisokau

I am going to contact a transmission specialist tomorrow but I suspect that a second hand transmission is the only way to go and even then I won't get out of it for under 5 or 6 grand I reckon.

On reflection, I really think you might have a faulty input speed sensor like several of us have had, rather than total TCM failure.
Here is a nice post with some technical details about the gearbox. Pages 4 and 5 of the "What problems have you had" thread might be good reading for you in general.

There are two input shafts, one for gears 1, 3 and 5 and the other for 2, 4, 6 and reverse. If a shaft speed sensor fails, the gears on that shaft are blocked. I reckon the fact you've lost 1, 3 and 5 (but still get 2, 4, 6 and R) points to that shaft sensor being dead, and the additional crazy things like showing gear 7, and the car going into reverse on startup, is it trying to do it's best when it can't select 1st gear.

For what it's worth, the speed sensor replacement is apparently a gearbox-out operation with about $1,500 of the bill being labour, so a gearbox swap might not be too much more depending on how much you can secure the second-hand 'box for.

Good luck. I hope Hobart has a transmission specialist as good as the one that has been diagnosing and fixing all our cars in Canberra

Originally Posted by Chrisokau

If I can get the Mondeo repaired I'll sell it. Sigh. Never again will I buy a car with a DSG gearbox.

It is a shame - these cars are usually pretty solid if you can get past any issues with the gearbox, and when the DCT is working properly it does drive wonderfully. A pity Ford didn't have the reliability truly sorted before public release. Unfortunately if the DCT goes wrong they tend to be very expensive to fix, and the car is clearly only any good if you can trust in it to work right...

[T-Pak Addict]

Here is a set of videos that may be of interest to those mechanically enabled.

https://www.youtube.com/watch?v=jxCE...bImw9Sg3mSPaT5

https://www.youtube.com/watch?v=XNgv...mSPaT5&index=2

https://www.youtube.com/watch?v=OOwm...mSPaT5&index=3