Vectra Crankshaft sensor help!

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bullstar
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Vectra Crankshaft sensor help!

Post by bullstar » Wed Nov 21, 2012 10:04 pm

Hi guys, well ive just bought my pico advanced picoscope great bit of kit and trying to get to grips with it :roll: Im doing a job on the Vectra 03 2.0 diesel DTH and it starts fine when cold then goes into limp mode when warm and my scanner is saying crankshaft sensor and and cam sensor! (don't think they have cam sensor)
So I've hooked the pico up to channel A with my blue bnc cable and put the black earth to negative on battery and put the acupuncture probe into the signal wire (I think) and run the automotive software for sensors/crank/inductive/running and when the scope starts it have 0 voltage or very little and wont even rise to 0.5 volts when engine speed is increased.
I'm I doing the test right or does it seem like a faulty sensor? Any help would be appreciated , regards Colin.

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Karl winter(KarlW)
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Re: Vectra Crankshaft sensor help!

Post by Karl winter(KarlW) » Wed Nov 21, 2012 11:16 pm

Bullstar,
I'm far from being a scope master but I think if you posted a psd file so all can have a look and see whats going on they could help you better. Also if its a VR sensor and you would like to see full amplitude you may want to hook scope ground lead to other side of sensor being neg side. Thats if it a floating ground sensor. Not fimilure with the vehicle your testing.

bullstar
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Re: Vectra Crankshaft sensor help!

Post by bullstar » Thu Nov 22, 2012 9:29 am

Hi thanks for your help I will try putting the earth on to the sensor directly today and see what results come up, Not sure what a vr sensor is at the moment as im new to this kind of work but will try that today and post what comes up and will try and upload a psd file, Thanks :D

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Karl winter(KarlW)
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Re: Vectra Crankshaft sensor help!

Post by Karl winter(KarlW) » Thu Nov 22, 2012 2:22 pm

:D
bullstar wrote:Hi thanks for your help I will try putting the earth on to the sensor directly today and see what results come up, Not sure what a vr sensor is at the moment as im new to this kind of work but will try that today and post what comes up and will try and upload a psd file, Thanks :D
bullstar,( VRS)= variable reluctance sensor. It produces a anolog(ac) signal. It also uses magnetism by way of a permanent magnet with a coil of wire wrapped around it internal to the sensor to generate a voltage signal. Higher frequency higher speed.
1. you can hook up to battery neg with scope and B+ to scope pos just keep in mind that you won't get a true amplitude of sensor. This method would be good for checking say cam/crank relations.
You should have got some kind of signal from either wire pin-thats if it is a 2 wire sensor.

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Robski
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Re: Vectra Crankshaft sensor help!

Post by Robski » Thu Nov 22, 2012 2:58 pm

OP what scan tool are you using ?

bullstar
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Re: Vectra Crankshaft sensor help!

Post by bullstar » Fri Nov 23, 2012 1:11 am

Hi Karl, Thanks for the info regarding the sensors, I looked them up and starting to understand a little bit :shock: Well this is the first time in using a pico but when I went back this morning had my thinking cap on! so went like this: I set the scope up and the crank sensor had 3 wires to it and when I probed the middle wire my scope jumped into action and got steady waveforms from 0v up to +8v and then down to -8v while the car was cold (my first waveform :P ) after the car had warmed up suddenly the car jerked went to limp mode and the sensor was reading 0 to 0.3v so thought this must have been the sensor coil braking down when warm. So I changed the sensor and it did cure the car but should I have tested the sensor its self some way in case it was a wiring fault, Regards Colin.

bullstar
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Re: Vectra Crankshaft sensor help!

Post by bullstar » Fri Nov 23, 2012 1:13 am

Hi Robski I was using a Autoboss V30 scan tool

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Karl winter(KarlW)
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Re: Vectra Crankshaft sensor help!

Post by Karl winter(KarlW) » Fri Nov 23, 2012 10:38 am

8) Colin, nice job.
Did you save psd file so you can throw it up for all to have a look?

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Autonerdz
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Re: Vectra Crankshaft sensor help!

Post by Autonerdz » Wed Nov 28, 2012 5:34 pm

I don't recommend you ever place the scope ground on a voltage supply unless you know exactly what you are doing. There is really no practical reason for dong so with Pico's channel math functions.

More on VRS scope strategy here:

http://www.picoauto.com/support/post26279.html#p26279
Tom Roberts
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Re: Vectra Crankshaft sensor help!

Post by watty74 » Thu Nov 29, 2012 10:26 am

I you are showing specific codes relating to the cam sensor the fault lays within the fuel pump, because the pump pulley is the same size as the cam pulley the ECU uses the reference from the pump to calculate cam position, this is a very common fault on the Y20DTH and unfortunately results in a replacement pump, (there may be specialists who can repair them now) and if memory serves the last one I did cost £1700 just for the pump, you can always do a basic timing check, this will eliminate any issues with timing, chain stretch etc,

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