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Greetings from Australia. I hope someone can advise me on this? I have a Renault Koleos 2011 2.5L H45 4WD CVT auto car, which globally is based on exactly other models - the Nissan X-Trail T31, the Nissan Rogue, Altima etc, so chime in if you can assist on those models too, as they're virtually the same car:

My Car Scanner Pro app I have on my iPhone is incredibly good.. it's currently showing the TCM unit (the Transmission Control Module) is reporting a speed of 193klm/h, even though the car is standing still, even when the engine is switched off. No other speed sensors report that kind of error, so what gives?

Does anyone know anything about this 193km/h fault, or how I can solve it? I've swapped out all 6 speed sensors on the car for all brand new ones and the error remains.

Any suggestions are extremely appreciated.

Thanks, Stu.

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  • Can you disconnect the TCM module to see if problem goes away? Commented Feb 14 at 20:41
  • Hey Bill.. good question.. I'll check and get back to you as soon as it stops pouring rain on my driveway! I do have another identical TCM unit I got from the wreckers, and when I plug that one in as a straight swap, the app immediately displays 242km/h, not 193km/h anymore!
    – StuMur
    Commented Feb 16 at 1:38
  • @BillSullivan Hey Bill - I unplugged the TCM and of course the live data graph instantly freezes. So I restart the app with no TCM plugged in, and the TCM vehicle speed reading now displays BLANK km/h. I might add that it doesn't display 0 km/h.. just BLANK km/h, which I figure are two different things? So I guess that means it's not registering in any way, as the TCM is disconnected? But anyway.. yes mate - the speed reading does disappear when the TCM is unplugged. What does that suggest, do you think?
    – StuMur
    Commented Feb 16 at 8:29
  • @StuMur- when you plug the swap unit in and it still displays a km/hr reading it is suggesting it is not the tcm module. Do you have access to a wiring diagram for this? Wiring problem or bad ground connections are what I would be looking for. Commented Feb 16 at 12:36
  • @BillSullivan - thanks Bill. I'm afraid I don't have a wiring diagram mate. One thing that's odd to me.. is that both the TCM modules both retain those exact numbers.. one is always at 193k's, and the other one is always at 242k's.. I figured each one would reflect wild values if it was a weird ground. In any case, today, the app told me my bluetooth adapter is a potential poor quality one (I thought it was decent when I bought it). It's doing odd things and I can't diag until I have a constant. So I'll report back next week when my new VLinker MC+ unit arrives - I'm told it's good!
    – StuMur
    Commented Feb 17 at 9:54

2 Answers 2

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This answer isn't vehicle specific, but should work. It would be helpful to have a scantool that can read live data from every speed sensor on the vehicle. Find out which one(s) is misreporting.I would assume that it is the speed sensor in the transmission, but not necessarily. When you find the bad signal using live data, you need to realize there are many places that can fail and cause this. Bad sensor, bad or dirty tone wheel(this is the part with teeth that spins underneath the sensor), bad wiring or connectors, no reference voltage to the sensor, a bad connector to the TCM or ECM or a bad TCM or ECM. You have only addressed one of these issues. Once you find the faulty circuit, then you can trace it down to one of these issues. Most of the time, you will find the issue caused by a faulty sensor, tone wheel, or damaged wiring or connectors.

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  • Jupiter.. cheers for the salient and logical reply mate - I agree entirely with all of it. One quick jump ahead.. what do you think it indicates if I have ALL 6 speed sensors unplugged (i.e. the input and output speed sensors on the cvt auto gearbox casing, plus the four speed sensors on each wheel - I think that’s all there is?), and the app still displays the same 193km/h error with them all unplugged? And also - I actually have an identical TCM module I got from the wreckers.. when I plug that one in, the error changes instantly up to 242 km/h!
    – StuMur
    Commented Feb 16 at 1:33
  • Again, I do not have the Vehicle specific info, but if the sensor in question uses a reference voltage of 5 volts for example, and if 0 volts is the parameter for the highest speed (242 km/h) then you may have a wiring problem. Seeing that there is a different reading between TCMs you might consider checking all pin connections at the TCM for corrosion or some kind of short in the signal wire. It would be extremely helpful if you could find a diagram of the circuit at fault.
    – Jupiter
    Commented Feb 16 at 23:01
  • Are there any fault codes?
    – Jupiter
    Commented Feb 16 at 23:50
  • Thanks @Jupiter.. I'll try again to find one. Update: My phone app today reported my bluetooth adapter as being a possible junk one (I thought it was good quality when I bought it!). It could be contributing to weird events.. so I've ordered a VLinker MC+ unit, which arrives on Friday. I'll report back then on my progress - hopefully it'll respond entirely differently! Thanks for your help so far!
    – StuMur
    Commented Feb 17 at 9:57
  • sorry mate, yes I'm getting codes, quite a few. I wanted to first work out why the app is reporting this 193km/h error with you guys before I went down the original rabbit hole I've got, but here goes: The CVT started slipping last week, and then went into Limp Mode 2 days later, and now won't move out of 1st gear. Reverse works great though. Codes are: P0725, P0746, P0826, P1701, P1778, and P0868. I get a random U1000 code too sometimes. I thought if I could clear up the 193km/h thing, I might lose some of those codes. Anyway, that's the full story - I hope that helps? Damned CVT!
    – StuMur
    Commented Feb 18 at 7:08
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Wow that last comment and what's in it changes this whole scenario. The first step in diagnosis is to study all fault codes and repair. If you were to repair this vehicles problems that caused fault codes, I am confident the speed reporting problem is related to at least one of the faults. You have a larger issue here than was originally posted. With that many faults and the types of faults, the first place I would look is at all the connectors at the TCM and ECM. Make sure everything is clean and hooked up properly. Then check power supply and speed input signals between the ECM and PCM. You may even have a bad TCM and\or ECM. I could go on and on, but at this point, you are probably better off looking for a shop that is good at diagnosing electrical in engine and transmission systems. But before you do, make sure your battery and charging system is working properly. Clean all cables from the battery, both ends of both cables clean them, don't just inspect them. Many times a poor power supply will cause this many problems. Also this must be done for a good diagnosis to begin.

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  • thanks mate, great advice. I'd ofc take it to an auto-elec near me, but where I live, they all have a 30-day wait, then charge like surgeons to start looking. The car's not worth $2k, so I'm sort of stuck doing it myself. I've got a spare ECU and TCM, I've swapped both of those on many occasions and the fault still remains. I've cleaned and reattached all the earth points I can find. The last thing I'll try today is swapping out the crankshaft sensor (P0725 code) (very hard to get to, so I've put it off), but I suspect the U1000 code is worse anyway, and I've no idea on that. :-/
    – StuMur
    Commented Feb 18 at 21:21
  • A wire diagram would help you a whole lot. If you're handy at using a multimeter, you can do testing on wiring and pin outs. Seems to me you have a signal problem. I think I'd start with checking for proper reference voltages and correct signaling from sensors to and from ECM. Good luck and let us know.
    – Jupiter
    Commented Feb 18 at 23:14
  • I agree mate. I'll try to find one. Bit of positive action today though.. I replaced the battery today as it was starting to fail, so the new battery seems to have cleared most of those codes up. Now, all I have left is a P1778 in the TCU, and a persistent U1000 present in the power steering, EMM, and Sonar modules. Do you know anything about U1000 codes? I reckon if I fixed that (cos it kinda seems serious), maybe the P1778 would bugger off too?
    – StuMur
    Commented Feb 19 at 9:46
  • There's been some weird electrical thing going on for ages too: the fuel guage often jumps around wildly, the rear electronic tailgate often unlatches on its own.. you get out and close it, and it unlatches again while you're right there. It's weird when that happens when you're sat in the car! Also, the dash has a wildly flashing "BRAKE SYSTEM ERROR" thing that flashes often.. and I can trigger it reliably by searching for certain sensors in the scanner app - search say 'wheel', or 'speed'. if it shows in the search results, the dash goes nuts. Pity I can't upload video clips or pics here!
    – StuMur
    Commented Feb 19 at 9:52
  • As Jupiter has stated, I think a wiring diagram now is crucial. A computer module or modules with bad ground or grounds can cause all kinds of weird electrical problems. Commented Feb 19 at 12:30

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