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  • The vehicle sensor thread

    Hey guys, seeing my specialty is with sensors and actuators on the vehicle I thought I would start a sensor thread.
    personly I prefer sensors over scantool data cause it’s true live data not perceived data.
    dont get me wrong scantool data is still great and very useful and on many occasions is the go to data.

    So if anyone has a general interest or wants some diagnostic approach on things make a request on what you want and I will do my best to put up info. If you are handy with a multimeter or even hand held mini scope this could be for you.

    I will start below with the position sensor for the boost control mechanism in the turbo also known as variable geometry vanes.

  • #2
    The pink wire in position 3 wire sensor will be give or take a little bit at idle 2v, under full load it will peak at 3.5v
    this will show full range of the VGT boost mechanism.

    If it soots up it will not go full range and or not be responsive to throttle. May also just be jammed on a particular voltage.
    you can test this with a high impedance multimeter.

    Comment


    • DaveC
      DaveC commented
      Editing a comment
      Thanks for sharing your knowledge Spook1205, keep it up!

  • #3
    Hi Mate. My turbo reads 5% at idle and a max of 65% on a hard acceleration and at high revs. Any problem here please? Reading from a small hand held scan tool.
    dave.

    Comment


    • Spook1205
      Spook1205 commented
      Editing a comment
      Hi Davidd, I think you need to check it out another way. It could be correct but scan tools are a computer program that reads OBDII program which reads ECU program which gets its digital data derived from an analog signal. Hence why I look at sensors.
      Do you have a multimeter? preference being a decent one because the $10 bunnings one will draw too much current being low impedance.
      If so we can either look at VGT position sensor or we can look at boost pressure from MAP sensor. I’d go VGT first.
      If not I can lend and send you a little hand held scope to test voltage whilst you drive. Send a vid on how to set it up and off you go.
      Scangauge2 works well for MAP readings too.

      If you PM me your details we can sort something out, put up final results on here for the guys to see.

      Cheers, Spook

  • #4
    i havent looked at the turbo closely , but is there a position sensor combined with the stepper motor mechanism? If the stepper was faulty would that also cause low sensor output?
    2016 GX , in White

    Comment


    • #5
      On turbo there is two plug connections

      Two wire plug which controls the variable geometry mechanism. It’s not a stepper motor as such but more of a pulse width operated solinoid like you would see on an EGR or a suction control valve. So more on time more solinoid responds.

      Three wire plug is your standard 5v analog sensor. 1 5v power supply an 0v earth wire and a variable voltage signal to be converted into electronic data.

      If turbo VG mechanism is seized or only has small movement the position sensor will reflect this.

      by looking at a good sensor signal and knowing its voltages it’s simple to test the VG operation. This can be put into the mix of info for diagnostic reasons.

      Comment


      • #6
        Attached is a table of expected DPF sensor voltage range.
        sensor voltages are an important piece of a diagnostic process.
        Yes a scan tool will log a DTC (Diagnostic Trouble Code) but it doesn’t say replace component, it’s a trouble code to say something has caused the circuit to go out of expected range.
        So with a high impedance multimeter or scope it’s the go to tool / test after checking your DTC.
        I saw a guy once put 3 airflow meters on a VL cause the DTC said airflow meter. It didn’t say replace airflow meter, ended up being a wiring plug issue.

        Comment


        • #7
          I’ll get to a wheel speed sensor during the week, what to expect and how to test. Also will explain why it’s different to your old typical analog sensor.

          Comment


          • #8
            The wheel speed sensor on the Fortuna is like all modern wheel speed sensors in that they are electronic rather than analog (simplest way to describe it).
            benifits are a clean signal at low speed so great for your downhill assist as among all the other programs associated like ABS, traction control, stability programs.
            They put out an .5v AC signal that switches with tone ring.
            Attached pics show how scope is wired in, spinning fast by hand and then slow.

            Comment


            • #9
              G'day Spook. I'm the 'top of the class idiot' when it comes to engines & the like. If possible, can you upload a photo of the DPF sensor & where I can find it in the engine bay.

              Can I check the DPF sensor with a multi meter to see if there's any probs with it? If so, what colour wire should be giving what read outs? I'm really interested in the DPF topic but not being a 'back yard' mechanic, its a bit over my head.... I'm more a car tinker-er.

              My previous 4x4 was a 3.0Lt series II GU patrol, (the hand grenade) model. Luckily mine never blew up, but I was very anul when it came to oil changes every 5ks & changing all 3 filters as well. I regularly had probs with MAF sensor having to get fault codes cleared regularly. I suppose that's why I'm interested in the DPF topic.

              Comment


              • #10
                Originally posted by Anthony View Post
                G'day Spook. I'm the 'top of the class idiot' when it comes to engines & the like. If possible, can you upload a photo of the DPF sensor & where I can find it in the engine bay.

                Can I check the DPF sensor with a multi meter to see if there's any probs with it? If so, what colour wire should be giving what read outs? I'm really interested in the DPF topic but not being a 'back yard' mechanic, its a bit over my head.... I'm more a car tinker-er.

                My previous 4x4 was a 3.0Lt series II GU patrol, (the hand grenade) model. Luckily mine never blew up, but I was very anul when it came to oil changes every 5ks & changing all 3 filters as well. I regularly had probs with MAF sensor having to get fault codes cleared regularly. I suppose that's why I'm interested in the DPF topic.
                Hi Anthony
                sorry this took a few days to get back to you. Please use a decent multimeter that has high impedance.
                range should be close to .8v to 1.2v when you rev it up in park. If it is higher than than this you can start to think you may have some issues. For driving the vehicle see table above.

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                • #11

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                  • #12
                    Thanks Spook, appreciate it. Not sure my $20-ish multi meter from Jaycar will do the job, but hey, just another toy to get... woo hoo!

                    Comment


                    • #13
                      Tried to put a video together on using a multimeter to test the DPF sensor. Hopefully it will give some clarity on what I talk about and why
                      https://youtu.be/bAnRmSj6OuE

                      Comment


                      • #14
                        Thx. Makes heaps more sense to those of us who failed finger painting at Kindy...

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                        • #15
                          The following links to the Denso Global site and which details CRD engine sensors, emission system components and fuel injection system components and more that Denso supplies to the diesel vehicle manufactures.

                          It's reasonably high level but it does cover all of the individual components (31 pages in all) but a couple of individual ones stood out.

                          - The fuel filter system shows a graph which details the efficiency of the current fuel filtration system and it further implies what micron level it can filter contaminates to.

                          - Although not fitted to the 1GD engines, it details a pressure sensor which measures the pressure of the exhaust gas immediately upstream of the turbo.

                          - 5th injector, (Denso names it exhaust port fuel injector) it notes that it has a 'T slot' outlet rather than the normal orifice type outlet - unaware what is fitted to the 1GD though.

                          Lots of good information in this pdf document and worth a read.


                          http://www.globaldenso.com/en/newsreleases/events/globalmotorshows/2013/iaa13/files/IAA13_.diesel.pdf

                          Comment


                          • Spook1205
                            Spook1205 commented
                            Editing a comment
                            Nice find mate👍
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