Hello

 

Does anyone have an engine wiring diagram that shows crank and cam sensors?

Does anyone know what the 3 wires for these sensors are? are any of them a body earth?

 

 

Thanks for any help

Sam

Pin 1 will be live . 2 will be sensor voltage. 3 will be earth. Not sure if 3 goes to body or through ecu first.

These wiring diagrams may help, BUT it's a 21Mb download so will take some time to load:-

https://drive.google.com/file/d/0B-q8oWU1tefoQjBKQ3ZzM3FKUDQ/view?usp=sharing

If you open it, I suggest that you save it to your computer.

thanks for the replies

 

does anyone know what voltage should shown on a multimeter at the cam sensor plug?

 

thanks sam

These type of sensors generaly only run on 5v so if you've be seeing around 5v and expecting 12v don't worry it's fine... between 4.5 and 5.5 is acceptable .... But could be different with different manufacturers ..... What's the problem your experienceing ??

no signal from cam sensor ..... cannot seem to find wiring fault tried 2 sensors and 2 ecus .... one shows 5v with and without engine running the other shows around 4.5 and the earth seems to have good continuity 

yep there both ok then reciveing around 5v so your power is fine from both ecus you have tryed so its either a earth fault which needs to be checked with voltage as you still can see contuniity in a faulty ciurcuit .... or a faulty signal wire back to the ecu which i take your car wont run so you would only be able to check when cranking so the best way it check that would be a scope reading using vcds or simular diag software ... you can also manually check it by checking the voltage the voltage when cranking depending on your meter it should pick up a voltage reading if its a pound shop meter (no offence) it might not be quick enought to show a voltage reading so thats where to old test bulb will need to come out to check it hope this helps a little

its not a pound shop one its a mid range multimeter lol but i understand your point ( no offence taken ) the engine does run off just the crank sensor but it takes a while to start off just one sensor .... the wire from the fuse box shows a solid 5 volts whether running or with ignition on...... the signal wire does regester a volt reading of around 4.5 and the earth goes through the ecu also ....

 

would it be acceptable to splice the wire or use a scotch lock to run a wire from the sensor earth to the battery to rule out the earth being bad even with it going through the ecu?

 

or is there a different way of doing this or something i should do first?

Edited 5 January, 201511 yr by Holmesie

sorry just been out to double check and the live wire is 5 - 5.05 and the load wire is 2.20-2.25

Ok and no I wouldn't say its a good idea scotching into it ..... To check you've got a good Earth on that wire I would take a voltage reading from the battery so say 12.1v .... Then put the negative wire from your meter on your sensor earth wire and the power wire to the battery power if you have a good earth so should see your given battery voltage with a max drop of 1.5v anymore and you'll be looking at a high resistance some where ..... Make sure the circuit is complete ie all plugged in

No sure what your voltage should be on your signal wire only skoda can tell you that .... I'd say 2v at idle is about right tho only thing you can check on that is weather the voltage changes with the revs .... And you say you've got 2v where's that at take a reading at the sensor then trace the wire back to the ecu and see if you've still got the same voltage at that end of the wire going into the ecu .....

The cam position sensor is a hall effect device, you should have a small AC voltage coming from it once the engine is running, something like 0.5V AC.

 

The three pins are:

 

Pin 1 (blue/black wire)  +12V

 

Pin 2 (white/yellow wire) AC Signal to pin 109 on the 40 pin connector at the ECU

 

Pin 3 (brown/blue wire) -12V to pin 101 on the 40 pin connector at the ECU

 

Set your multimeter to AC V and measure the output from the middle pin of the sensor, also check it at the ECU end to eliminate a wiring fault, you can do this easily by pushing a fine sewing needle through the insulation of the wire and measuring from that.

For the benefit of those who see "HALL EFFECT" , and get baffled. A Hall effect device is a small semiconductor device that acts as a switch in the presence of a magnetic field. ( very basic idea of working).  For more detail see http://en.wikipedia.org/wiki/Hall_effect_sensor.