Powershift data logs and P0715

[Mondaveo]

Hey there Austenite,

Yes, I did go with the independent specialist for the repair - Auto Torque in Phillip ACT.

Their invoice (in 2016) was fully $1K cheaper than the Ford dealer quoted - $2,429.17 versus $3,427. Labour was the biggest component of the cost, as the transmission needs to be removed from the vehicle, partially disassembled, and then everything put back again. Auto Torque charged $1452 for 11 hours, vs $1740 quoted by the dealer (my quote doesn't say how long, but I was told they discounted 3 hours).

Parts and consumables cost about the same (speed sensor $580 vs $530, transmission fluid $290/7L vs $250/6L), but Auto Torque had fewer items on the list. Ford's quote contained over $600 worth of additional items including a second sensor, transmission cover kit, and for some reason, coolant. When I queried this, they simply told me that this was just what the supplied list specified for rectifying the P0715 fault.

Which brings me to the other reason I chose the independent, they actually knew what they were dealing with and had a record and testimonials for fixing several Mondeos before mine (including those of some members on this forum). So I had more confidence they would actually put it back together right. The dealer on the other hand seemed to be guessing, to the point where (as detailed in this thread) I basically had to diagnose the issue for them, and then they received (probably) one-size-fits-all instructions from the mothership. Then expected me to pay for (probably) the on-the-job learning for the technician doing it for the first time...

[bundybear75]

Originally Posted by Austenite

When you got it repaired, was it at the specialist? Care to share the name?

I now have the same problem in Brisbane, Ford Springwood just quoted $5,500 (including clutch replacement, car now has 170,000km) and am on the hunt for a price closer to yours.

General mechanic next door said he'd quoted similar for the same model, and thought his trade price from the specialist would be about $4,000.

Will let you know how I go!

My experience was much the same as Mondaveo. Same specialist. Same price.

A clutch replacement was not part of our repair, so this might account for the extra cost. I enquired about it as i had 134K km but they said it wasn't required and the clutch was in a different part of the transmission to where the sensor is and required more dismantling.
What is prompting the clutch replacement? Mine is starting to get a bit grabby on takeoff so I'm wondering if mine might be on the way out. (310K km)

Also, my repair was 4 years ago, so prices would of increased.

My advice would be, if you get the repair done, get them to change the rear main engine seal whilst they are in there. Mine developed a leak not long after my transmission repair, and it seems to be a common problem, and a transmission out repair.

[Austenite]

Thank you both, much appreciated!

I haven't actually started looking for other specialists yet, since I've driven the car for about 50,000 km with the issue, mine might not be too bad. Considering the age of the car I'm tossing up whether to keep driving it until someone crashes into me.

[Highway cruser]

Originally Posted by Mondaveo

Ah, thank you my man! That changes the interpretation of my graphs and could be a breakthrough. If input sensor = "RPM" then I should see any evidence of the erratic signal on that line, rather than the line for "GISS" as I'd thought. And indeed I do have a squiggly trace for "RPM" in many instances where the gearbox shifted awkwardly. I had attributed that as a result of changing engine load with the clutch dis/engaging but it looks like it could be the evidence I was seeking.

The interesting thing now would be to compare the "RPM" exposed by the TCM with a recording of the actual RPM at the engine (ECU?). Unfortunately I don't think FORScan allows me to live stream from two different modules at once...

(BTW, I think you mean Bundy's photo?)

morning gents,

I've been having issues with harsh shifting for a long time and have followed this thread for almost as long. Having some time to spare at the moment I thought I would have a further look into the issue I'm having as it doesn't look like anyone has actually done a repair/fix on this yet, apart from sending to a gearbox specialist or selling the car, neither have I but I believe I have worked a few things out.

I'm getting P0715 basically all the time as well as the harsh shifting and jerking on take off, but have only ever had limited transmission function come up on the dash once.

On a slightly different note, what's everyone's thoughts about the chances of my issue being related to contamination on the GISS sensor?

From the graphs I believe the RPM line in the opening graphs will be coming from the bell housing that then plugs into the TCM. The GISS is a sensor in the mechatronic unit which can be referred to as the input speed shaft sensor. I'm pretty sure this is the sensor that I'm having problems with as well as Mondaveo had. This is based on the fact that when the car is stopped you can see on the graphs the value for the GISS goes to 0 RPM, meaning that both clutches are off and no drive is going to the gearbox. This is based on graphs I have taken.

Based on the fault code and the GISS sensor being in the mechatronic unit I believe that the reason that Mondaveo was quoted for coolant is that the mechatronic unit can be removed from the gearbox without taking the gearbox out, it does mean draining the coolant, hence the need for coolant on the quote. However the quote I believe shows the wrong sensor. based on the pictures of the part they quoted, this is the RPM sensor on the bell housing. At the moment I haven't tracked down the correct part number for the GISS.

It seems that the GISS sensor only reads input shaft 2. Based on both output shafts being connected to the main diff gear, both input shafts will be turning while either of the clutches or any forward gear is being used as the there's always a second gear selected. I can only assume that when its using a gear on input shaft 1 it works out the correct speed of input shaft 2 based on the gear ratio between the gear in use and the next selected gear.

I have tracked down a series of YouTube videos of the mechatronic unit being removed for a different issue, but it does show how to remove it, however not how to change the GISS sensor. link to the first video is here: https://www.youtube.com/watch?v=jxCEdxT2_Rk

I've also tracked down a manual for the 6DCT450, I've tried to attach to this post but it didn't work for some reason, but if you want a copy let me know.

It would be interesting to hear peoples thoughts on this.

[Austenite]

Originally Posted by rondeo

6DCT450 Technical service manual pdf:

no longer working :(

Updated link:
https://godsskill.files.wordpress.co...rvice-menu.pdf

[rondeo]

My expertise re the dct450 is limited to reading the manual by ATSG and Ford.

I suppose the GISS sensor is a hall effect device. In other word an electromagnetic sensor. From a purely speculative point of view it seems plausible that metallic contamination of the transmission fluid might interfere with the working of the sensor.

In any case there's one sure way to see if there's any fluid borne deposit of metallic particles: take a look, unfortunately.

Another permutation is that the hall effect sensor is dead, that would be a permanent malfunction.

An intermittent contact or bad connection may also be suspected.

Surely your local Ford dealer can tell you what the GISS sensor part number is?

Looks like you have a good handle on the issue anyway!

[Mondaveo]

Originally Posted by Highway cruser

I'm getting P0715 basically all the time as well as the harsh shifting and jerking on take off, but have only ever had limited transmission function come up on the dash once.

On a slightly different note, what's everyone's thoughts about the chances of my issue being related to contamination on the GISS sensor?

From the graphs I believe the RPM line in the opening graphs will be coming from the bell housing that then plugs into the TCM. The GISS is a sensor in the mechatronic unit which can be referred to as the input speed shaft sensor. I'm pretty sure this is the sensor that I'm having problems with as well as Mondaveo had.

The text associated with the P0715 code (at least that which I saw) was "Turbine/Input Shaft Speed Sensor A Circuit - Signal Erratic". I believe other sensors will get a different DTC number. So if you experience poor shifting behavior, and you have P0715, and you can observe implausible data coming from the sensor, then the fix is to replace that Sensor A.

Now there is conjecture about which is actually that "Sensor A", of the data sources exposed in FORScan I initially assumed it would be the one named "GISS", but out of the discussion on this forum it emerged it may actually be "RPM". The graphs I made did seem to show erratic readings coming on that RPM trace, but we never established definitively that this was the source nor which physical component it corresponds to. Anyway, I do know the Auto Torque techs who did the repair did also observe implausible data as part of their diagnosis procedure, whichever sensor that was.

When you say "no one has done a repair/fix", you mean as DIY? Because cars have been fixed, clearly, it has just required getting professionals to do the work.

I'm satisfied I've understood the fault and the repair even if not knowing all the details and nomenclature of the what and how. I'm pretty sure I read an article or saw some YouTube video or two about the disassembly and repair of the Getrag 6DCT to learn some details (e.g. I know there's special alignment tools required to put it back together), but I knew it was far too heavy a job for me to do personally so I stopped there. Are you planning to establish a procedure to DIY?

[Austenite]

Originally Posted by Highway cruser

I'm getting P0715 basically all the time as well as the harsh shifting and jerking on take off...

I have tracked down a series of YouTube videos of the mechatronic unit being removed for a different issue, but it does show how to remove it, however not how to change the GISS sensor. link to the first video is here: https://www.youtube.com/watch?v=jxCEdxT2_Rk

Got super excited and thought you were on to something. In the technical manual it shows the imput speed sensor as reading the clutch drum housing, mated up to the flywheel. I think this is why the gearbox needs to come out to replace the sensor :(

However, if you could access the plug at the TCM using the method shown in the video, and somehow access the bell housing, might be possible to replace without removing gearbox?

[Austenite]

This YouTube video shows the gearbox being disassembled and reassembled - the input shaft speed sensor is buried deep in the gearbox - no replacement without removing the gearbox. :(



https://www.youtube.com/watch?v=I9vIr-9PG10