BKD eating cam sensors

nztdi1

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Mar 29, 2015
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nz
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golf mk4, touareg 2.5, octavia 2.0 8v, boats x2
Hi everyone

Have a BKD 2.0 twincam in a boat which has been giving a code for an intermitant camshaft sensor implausible signal. Have double and triple checked timing and replaced the sensor which appeared to work at first but the code came back within a few minutes and now reappears immediately after being cleared. Have tested the factory wiring to the ecu and it appears fine but i have bypassed it anyway. Is it likely my new(aftermarket) sensor was just a dud? or might something other than the wiring be killing them? sensor ring looks fine to me, i have everything run to a single earth point and all looks good. any suggestions other than just throwing another sensor at it? it actually runs ok, just don't trust it enough for a marine application knowing its throwing a code. Any advice would be greatly appreciated
 

Franko6

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May 7, 2005
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A similar event we have had with BEW engines is a bad ground wire in the harness that goes to the acorn nut near the ECU location. I can only guess you built a harness that eliminates a lot of the scurious mess that would come with the automobile wiring.

Depending on the aftermarket sensor, I wouldn't be too sure, but the original ones for several versions were built by the Chinese and were particularly prone to failure; for example, the BHW crank sensor has a fairly long lead and the insulation would crumble. We use the FTE brand, which I can't promise you is not made by the Chinese, but at least I think they improved the insulation material.

I can't access the BKD wiring diagram from Mitchell's, which is a schematic style diagram. It's much more user friendly than the Bentley. The BHW engine shows pins for the #27, 28 and 29 on the ECU coming from the cam position sensor. Wiring color code is:
#27= red/ white
#28= violet/ blue
#29= Brown/ yellow

Maybe there is no coordination between the BKD and BHW engines. But apparently you have the ground solid, so it's a matter of the three other wires, which go directly from the cam position sensor to the ECU. I've never seen an ECU cause an intermittent for the cam sensor. It's always the wiring, so far.

Add to your mix, it's a ocean/ marine application? Good luck. I would be inclined to make the leads very short and the wiring and ECU waterproof as possible.
 

eddieleephd

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I am curious if the crank sensor is actually the issue. Implausible means unexpected and is compared to the crank sensor as far as I know.
 

nztdi1

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Mar 29, 2015
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nz
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golf mk4, touareg 2.5, octavia 2.0 8v, boats x2
Thanks for the replies guys.

Frank- Yes there are 3 wires from sensor to ecu, black/white, brown/green and violet/brown from memory can confirm if it's useful though. i have a diagram but have not been able to find any info on which wires are earth/sensor/power, but i can test it anyone can suggest a procedure. Might there be expected voltages? i have run new wiring for all 3 from the ecu to the sensor plug and even bypassed the plug with the old sensor to double check. i will strip the wiring and check the one connection i made between the factory earth wire and my single earth point. I would expect to have a range of issues if it was bad upstream of the ecu though?


I have ordered 2 new sensors just to be safe(mainly because they take forever to get here and i'm sick of waiting for parts!) a secondhand genuine one and a new Febi one which should be better quality than the one i have now. Fingers crossed i don't just fry them! Wiring is well wrapped and ecu is in a waterproof box so should be ok hopefully.

Eddie- I was wondering the same thing and hope it is not the case as on the BKD they are integrated into the RMS and i believe require a special jig to replace? I did notice when i first started it with the new sensor it fired up instantly so hoping it is in fact the cam sensor but will keep that in mind
 

eddieleephd

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Joined
May 27, 2012
Location
Battle Ground, Wa
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2002 jetta Wagon
Thanks for the replies guys.

Frank- Yes there are 3 wires from sensor to ecu, black/white, brown/green and violet/brown from memory can confirm if it's useful though. i have a diagram but have not been able to find any info on which wires are earth/sensor/power, but i can test it anyone can suggest a procedure. Might there be expected voltages?
Based on experience with VW wiring brown with stripe should be Earth and the other two the circuit conductors.
Also based on experience, check the wires into the plug, they like to break there.
I honestly recommend getting some plug repair ends in case you need to rewire the plug itself. Go to a junk yard and get a few plugs with a lead on them.
You just need the right size connector for the plug, although the right plug is nice to have a spare of.
 

nztdi1

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Mar 29, 2015
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nz
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golf mk4, touareg 2.5, octavia 2.0 8v, boats x2
Thanks Eddie

I poked a small wire into the ecu plug and checked continuity of the 3 wires and all seemed OK. Pins in the ecu look OK too. Might be possible to run the earth wire externally instead of through the ecu? What goes on inside that magic box is beyond me! At this point I think I'm just going to have to triple check my earths and try another sensor and see what happens unless there is a voltage test I can do coming from the ecu?
 
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