I’d be very interested to see the information produced by the IID tool during data capture. Does it record the measurements as a .csv file, like the Faultmate? It’s important to recognise the limitations of this method, though, as clearly only the current being fed to the solenoids is measured and not the resulting pressures produced.

Essential data for the 3-4 shift analysis is :

Three speed signals (engine, turbine & output)
Solenoid currents for EDS2, EDS4 & MV1

Clearly the capture rate is critical as we’re trying to see what’s happening over only a couple of seconds.

Can you post up a list of the descriptions that the IID tool assigns to the solenoids? Does it not use the ‘EDS4’-style designation?

Ultimately it may be best to send the mechatronic unit to Pete Stirrup at Valve Bodies UK for him to test on one of his four Hydra-Test machines. This would then provide us with the actual hydraulic pressures being generated and the machine would immediately flag any anomalies. You would then know if the fault was with the control system or if it was an issue with the hardware (clutch packs, internal seals, etc.).

Phil

I've only had the IID for a few days so not very adept at using it yet. However, a scan of the user manual shows that the device presents the results in graphical form (on a tablet) but it also says that the data can be exported in .csv format.

I'll see what I can do. Six elements should give a reading every 0.375 seconds so not too bad.

The IID TCM section has Engine Speed, Turbine Speed, Output Speed, Shift Lock solenoid (on or off) and "solenoids 1 thro 6" which each have an on/off element and a "Pressure" element measured in Amps (which I've played with and show between 0 and 0.8A in operation).

I had no idea that there was anyone in the UK with the skill and equipment to do that level of diagnosis. That is brilliant info. Thanks!

Will get back to you next week. 2008 TDV8 Vogue

I look forward to seeing some numbers – I’ve never seen the IIDTool’s capability at data capture before.

The ‘Shift Lock solenoid’ must be the black-cap MV1 solenoid then, as it’s the only ‘on-off’ solenoid in the mechatronic unit, the other six (blue & yellow caps) all being variable/proportional pressure solenoids. I’m assuming that the numbering system used by IIDTool for these EDS solenoids is the same as ZF’s. i.e.

1 = A clutch (yellow cap)
2 = B clutch (blue cap)
3 = C brake (yellow cap)
4 = D brake & E clutch (blue cap)
5 = main system pressure (blue cap)
6 = torque converter lock-up clutch (yellow cap)

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Hi Phil,

I tried to get some data capture last weekend but failed miserably! I suspect that this was partly my inexperience with the IID, partly because I wasn't seeing what I thought I should be seeing and partly that I was struggling with the logic of half the solenoids working one way and half the other so was not sure if I should be triggering on a rise or a fall of the control signal. If you've ever seen the episode of Red Dwarf where Kryten's head explodes - that was me!

The first interesting observation was that the "shift lock solenoid" shows as "On" when in Park and "Off" in every other situation. If I'm understanding correctly this can't be right as we'd never engage the E clutch if it were true?

Also, I've been using a PDF I found entitled ZF_6HP26X_LR_Description_and_Operation which suggests that Solenoid 4 should be "On" in all selector positions except D2 and D3. However, mine shows as off (0.7A) in P and N too.

Too many uncertainties to be confident of getting any sensible data at present. If you can shed any light on the above it would very useful from an "understanding what's going on" perspective.

In the meantime I've spoken to Valve Bodies UK and am waiting for a slot at my pal's garage to pull the unit out of the box (again!) so I can get it sent off to them. 2008 TDV8 Vogue

There are two types of mechatronic unit used in the 6HP26; the M-type and the E-type. The M-type has a cable-operated manual valve and park lock, as per the Range Rover. The E-type has an electrically operated park lock and doesn’t therefore require a traditional gear lever tugging on a cable and instead can use an electrical rotary selector dial e.g. as used in the 4.4 TDV8 for the 8-speed 8HP70 transmission.

The E-type mechatronic requires two additional MV (on-off) solenoids to operate the park lock and I’m wondering if this is where the confusion lies i.e. the ‘shift lock solenoid’. However, the 6HP26 Range Rovers don’t have the additional MV2 & MV3 solenoids, only the MV1 which should be activated in 4th, 5th & 6th gears for the E-clutch.

Because EDS4 is a blue cap solenoid its actuation reduces the pressure going to the clutch & holding valves which activate the D & E clutches (which one of the two is selected depends upon the position of Shift Valve 2). 2nd & 3rd gears are the only ones where neither the D-brake or E-clutch are applied and therefore D2 & D3 are the only ratios where EDS4 is activated. The definition of ‘on’ is slightly ambiguous for a blue cap solenoid because feeding it zero current means it transmits full pressure (4.6 bar) and applying full current (700mA) produces 0 bar pressure. Therefore, not activating the solenoid means that it is ‘on’, if you see what I mean.

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Regarding the ‘shift lock solenoid’, another possibility is that this is a complete red herring and it’s actually referring to the interlock solenoid on the shift lever, which prevents you moving the lever out of Park or Neutral without first putting your foot on the brake? i.e. nothing to do with the mechatronic solenoids

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You've got it in one Phil! I've just been and tried it again and it goes "off" with the brake not when lever is moved out of Park.

However, as far as I can see none of the other traceable elements available look like they might be the MV1 solenoid. I'll put a post on the IID tool thread and see if the developers can suggest why?

I worked out how to do a manual capture whilst driving along earlier with the IID looking at all six solenoid pressures. I have an Excell file of the results with the 3-4 shifts highlighted but for some reason I can't seem to upload anything to fullfatrr (get "Error retrieving album data" msg).

Tomorrow I'll try to get a "triggered" trace with elements you requested (less the MV1), perhaps using the parameters:

Start - 2 seconds before EDS2 activates
Stop - 3 seconds after EDS4 activates

and see what that tells us.

John 2008 TDV8 Vogue

Very interesting thread.

Please keep us updated.

Kudos for trying to locate the root cause rather than just changing the ‘box out.

Have you had a scan of the Sonnax website? Some interesting info on there 2007 3.6 TDV8

Phil,

Couldn't get the IID trigger facility to work but took a trace with the 5 parameters available and have highlighted the 3-4 shift periods with a yellow background:

https://drive.google.com/file/d/1zhkew0CxJ...sp=sharing

Does that give us an insight into what's going on? How does the data captured compare with the Faultmate? Nothing from the IID guys as yet re MV1.


Cheesels - Yes have seen the Sonnax site though it seems to be aimed more at the RRPhils of the world than Joe Public. 2008 TDV8 Vogue

All six of the 3-4 upshifts that you measured appear to be highly consistent:

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The IID tool can log engine rpm and turbine rpm

Would be very interested to see this data logged alongside the original capture 2007 3.6 TDV8

Thanks Phil,

The graphs seem to confirm what I'd read into the figures. In fact, when viewed on a graph they look so good I wondered if I was tracing the correct shift! The fairly rapid drop in engine revs shown doesn't seem to match how it feels in the car. You can see in graphs 3 and 5 it takes a little longer and I guess that's what I'm feeling but it's much more pronounced than the graph would have you believe.

In all the other graphs the engine revs are down to c1900 revs at about the time EDS2 is fully on but in 3 and 5 its takes another second or so to get down to proper "4th gear revs".

I can confirm that that EDS1 pressure is rock solid (with the same caveat as you note for the E clutch) as can be seen in this trace:
https://docs.google.com/spreadsheets/d/12U...sp=sharing

Also, as all the solenoids have just been replaced and this made no difference to the 3-4 shift I suspect (in the absence of hard fact - no word from GAP as yet) that MV1 is operating correctly.

So, as you suggested earlier, it's now looking like either a hydro-mechanical issue within the valve body or something causing a loss of pressure within the box itself or the E clutch itself - though that seems fine once its fully engaged.

I'm hoping to get the mechatronic out and off to Valve Bodies UK today/tomorrow.

Should I replace the four little tube seals again or should they be OK as they only been in a couple of weeks?

Cheezels - the engine and turbine speeds are shown on the graphs. 2008 TDV8 Vogue

The rubber jump tubes are usually changed as a precaution because they may take on a permanent set after being compressed for several years at high temperatures. I wouldn’t have thought you would need to worry after only a fortnight.

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Thanks Phil,

Valve body now out and en-route to Merseyside. Should be back on Friday but I won't be able to get it back in before Monday earliest. Will update as soon as I have.

On a potentially related point - I had a couple of instances of "Transmission Failure - Limited gears" The weekend before last. Fortunately I had the IID plugged in and measuring the Oil Temp. It enabled me to understand why this only happens when towing up a long ascent on a hot day. The temperature rose steadily from low 80s into the 90s and very soon after it got over 95 I'd get the message.

I've not been able to find any definitive info as regards what should be considered normal & maximum running temperatures for the 6HP26 so not sure if this is correct gearbox operation (i.e. going into limp mode because the cooling system isn't doing its job) or if 95C should not be a problem and this may be another symptom or issue caused by the oil thinning as it heats up?

Can you shed any light re working temperatures?

John 2008 TDV8 Vogue

The transmission cooler is an oil-to-water type which uses the engine coolant to cool (& heat) the transmission fluid. Consequently the transmission fluid normally operates at around the engine coolant temperature. 95°C is therefore not a high temperature for the transmission fluid, it is ‘normal’. Only once the fluid temperature gets above 125°C does the controller start to make adjustments to shift points and torque converter LUC operation (i.e. cooling strategy mode) in an attempt to bring the temperature down. If the fluid temperature gets to 137°C then the engine torque is significantly reduced and the transmission selects limp home mode. If it gets as high as 140°C then the solenoids are de-activated. Damage will occur to the mechatronic unit at temperatures above 150°C.

Phil