What's this Lexia error?

[Mandrake]

Hi Mike, I saw your PM but thought it best to reply here since I don't really have an answer to your question and possibly someone else does.

Depending on what sort of sensor it is you probably can't test it with an ohm meter. It could be a hall effect sensor or a variable reluctance sensor, and it probably has internal circuitry in it as well, which would definitely preclude any sort of simple ohm check.

I'm afraid I don't know the specific design/type of the crank sensor for that engine, if it was the same engine as mine I could at least measure my one.

If you've already got a new one I'd just go ahead and do whatever it takes to replace it, if you have to cut the wire on the old one so be it. If you cut it a couple of inches from the connector and thread it through the troublesome loop you can potentially splice it together again with crimp joiners anyway.

[addo]

Trois cent soixant Ohms.

[KP]

Could always swap all my V6 parts for this activa if you want I can pop up with them all on the trailer and bring the car back, save you more agro and 1 car parking space :p

On a serious note the crank sensors are known and are a PITA to replace as its just fiddly but i think where they are and the heat they get soaked in sometimes and then freezing overnight temps in winter finally kills them off. An undertray seems to help some petrol ones last longer but not by much.

[Mandrake]

If its the same sensor as mine pin 3 is the cable shielding, so isn't connected to anything at the sensor end, except maybe the housing if its metal, but I suspect its plastic. So you won't get any reading between pin 3 and the other two.

If addo is right about the resistance you should get a reading between pins 1 and 2. I haven't had a chance to measure mine and not sure when I will so I'd go with addo's figure. From looking at the symbol on the wiring diagram and the suggested reading of 360 ohms it would appear that its a variable reluctance type sensor which is basically a coil of wire with a small magnetic core which generates a voltage when alternating teeth and gaps pass by.

When I measured the output of mine on a scope (with the engine running) a few weeks ago it was quite high - somewhere in the 5 to 10 volt peak to peak range with a rounded off triangle waveform shape. I didn't measure its resistance when unplugged though.

[Mandrake]

What ohm ranges do you have ? Probably 200, 2000, 20000 etc ? You want to use the first range that is bigger than the expected value, in this example the 2000 ohm range - which can measure up to 2000 ohms since we're expecting 360.

If you short the probes together you should get close to zero (typically 0.5 ohms due to the resistance of the multimeter leads themselves) while disconnected you'll get some non-numeric reading indicating that the reading is out of range.

[addo]

Yes, measure between pins 1&2. Leave 3 out of your worries.

[Mandrake]

Sounds about what i was doing. I was using the 2k setting, the machine reads some value when probes touched together, when apart it returns to '1'. No reading when touching any combo of pins.

Try the ranges higher than 2k to see if you get any reading. Does sound like its faulty, however it can't be entirely open circuit or the engine wouldn't run at all.

Is the crank sensor only used at startup cos the car once revving greater than idle sounds ok but performance is flat. Took a good few cranks to start the last time she was fired up though and wouldnt idle. Hope this does the trick.

No the crank sensor is needed all the time - without it the ECU doesn't know where TDC is or how fast the engine is turning! It's critically important for ignition and injection timing.

The output voltage of a variable reluctance sensor increases the faster the engine spins (as well as the frequency increasing) so if it was faulty causing a very low output voltage it could potentially still be enough for it to run at higher rpm but struggle at lower rpm. So a high resistance faulty crank sensor would certainly fit your symptoms. Fingers crossed.

[KP]

Nah, i only break if its too far gone and the body was too far gone, with both inner and outer sill on one side certainly shot the other wouldnt be far behind and rear outrigger/c pillar mid sections being rusted it would be almost a cut and shut by the time it was done!

It was all original though as some bolts proved lol!

I quite like the idea of another activa after my last one died

Offer is there if you Fancy it

[myglaren]

Hope this isn't too simplistic Mike but there are tons of guides on YouTube.

[KP]

If they haven't been changes in that long and such low miles I bet they aren't happy and for the price a change is cheap enough.

The boost pressure could be the turbo over boosting. Drive the car gentle and off boost as best you can and see if the light stays off. If it stays as a permanent fault then the pressure sensor is possibly faulty.

Maybe if Jim pops in he will probably know what it's pointing to