Camshaft Position Sensor no signal

[Fraz]

Hi guys,

Hopefully someone can help. I have a 2004 Leon Cupra TDI which drives ok at the moment, bit down on power and has a starting issue which means it turns over 10 or so times prior to starting. Bit weird but always starts... SOOO

VCDS lite brings up a fault code of p3007 Camshaft position sensor no signal.

So far I have -

Changed the camshaft sensor (2 different ones)
Check wiring, found a break, fixed it
Im getting good continuity for the earth on the plug, 12v on the power on the plug however no voltage from the ecu at all on the signal pin at the plug
I have continuity from the ecu pin and plug pin for the signal.

STILL same fault code appears...

SO it appears the ecu is not feeding the signal pin voltage (Im led to beleive its meant to supply around 5v???)

Anyone have any other clues for me to try.. I find it hard to beleive the ecu would suddenly stop supplying the signal pin with a signal....

 

[Seatmann]

It might have but I wonder if there's some other signal missing to the ecu that then goes through it and out to the sensor? I really don't know myself, just throwing suggestions out there, maybe you could find a pin out diagram and check other stuff.
I would check all the fuses too

 

[mty12345]

Hi mate, not sure if this'll be of any help but if you do think it's your ecu then these guys might be worth a call, they tested and repaired my mates ecu a couple of years ago on his vx220 for £150, and think they charged £60 to test them if the repair wasn't needed. Maybe give them a call and see what they've got to say if you're sure it not the wiring or sensor. http://www.ecu-express.co.uk/index.htm

 

[Fraz]

Thanks guys,

Im struggling to find a wiring diagram to check

 

[Seatmann]

You could try here

http://www.ecuconnections.com/


and it might be worth starting a thread on the tdi club, there are folk around there that are good at these sort of problems but it can take a bit before they see the thread.

 

[grahams81]

Hi guys,

Hopefully someone can help. I have a 2004 Leon Cupra TDI which drives ok at the moment, bit down on power and has a starting issue which means it turns over 10 or so times prior to starting. Bit weird but always starts... SOOO

VCDS lite brings up a fault code of p3007 Camshaft position sensor no signal.

So far I have -

Changed the camshaft sensor (2 different ones)
Check wiring, found a break, fixed it
Im getting good continuity for the earth on the plug, 12v on the power on the plug however no voltage from the ecu at all on the signal pin at the plug
I have continuity from the ecu pin and plug pin for the signal.

STILL same fault code appears...

SO it appears the ecu is not feeding the signal pin voltage (Im led to beleive its meant to supply around 5v???)

Anyone have any other clues for me to try.. I find it hard to beleive the ecu would suddenly stop supplying the signal pin with a signal....

Think you've got it the wrong way round mate, the signal will be coming from the sensor not coming from the ecu.... i.e the power and ground supply the sensor with the power for it to operate then when the sensor sees what it wants to see it will switch voltage on or off to the ecu, depending if it's normally open or normally closed.

You could try and pull some of the insulation back on the signal wire coming back from the plug (just enough to get a reading from the wire) and try turning the engine over by hand or crank it and look for a pulse (you may need a good multimeter and set the input to manual ranging and look for the voltage - some multimeters are auto ranging and normally take a second to adjust to the correct voltage so are too slow to detect high speed pulses.... You may need a scope)

Also i take it that the sensor is checking the camshaft is in time with the crankshaft position sensor, if the sensor is working and feeding the ecu correct then maybe its showing you the timing is off - have you just changed the timing belt ? Or maybe has it jumped ?
I don't know a great deal about the derv lumps but the 1.8t uses a hydraulic tensioner for the camshaft chain and it can cause timing errors if the oil pressure is low or if the hydraulic unit is knackered.

Good luck bud.

 

[grahams81]

Just re-read your post, starting issue and down on power i would defo check the timing first, maybe the code is saying the signal is missing as in its not there at the right time. Just a thought.

 

[cocadave]

I had same fault code as you after i had changed the cam and accidently bent the timimg marks on the plate behind the cam pulley which caused the plate to wear a groove in the senser, all i did was to change the senser and reset the code, jobs a good one!!!

 

[Seatmann]

I had same fault code as you after i had changed the cam and accidently bent the timimg marks on the plate behind the cam pulley which caused the plate to wear a groove in the senser, all i did was to change the senser and reset the code, jobs a good one!!!

Read the first post again

"Changed the camshaft sensor (2 different ones) "

 

[cocadave]

Read the first post again

"Changed the camshaft sensor (2 different ones) "

Were they new? I don't know, I only gave my account of what my experience was, who's to say that he (or garage) hasn't had some engine work and possibly bent one of the timing markings like I did?
If they are bent changing the senser wouldn't solve anything as it would be destroyed very quickly if it was coming into contact with anything.

 

[Seatmann]

Were they new? I don't know, I only gave my account of what my experience was, who's to say that he (or garage) hasn't had some engine work and possibly bent one of the timing markings like I did?
If they are bent changing the senser wouldn't solve anything as it would be destroyed very quickly if it was coming into contact with anything.

Lol I'm not having a go

 

[cocadave]

Lol too, my bad

 

[Fraz]

Thanks for the ideas guys, Ill be having another look at this tomorrow.

The more I think about it the more I think Graham is right about the sensor. I did notice the sensor itself sits at a funny angle to the pulley. Ill have a better look tomorrow and see how she blows...

 

[Fraz]

RIGHTO...

Tempted to give up with it now..

checked the tabs etc, all is well and the sensor sits just a few mm from them perfectly so all seems well with that...

Does anyone have a wiring diagram for the sensor??

 

[Muttley]

This is a Hall effect sensor, which only feeds back a signal when the camshaft is rotating.

Three pin connector, the outer two should be battery voltage when ignition is on - pin 1, the flat side of the connector, should be low. Signal pin in the middle goes to pin 109 on the ECU. There will be no signal present.

There should be no continuity between any of the pins and each other. With the ECU connector removed, there should be no continuity to earth. The Hall sender itself is at the offside end of the cylinder head, under the toothed belt cover.

 

[Fraz]

Thanks mate..

What I've found today is im getting roughly 6-7 volts over pins 1 + 3..

I've traced pins 2 and 3 back to the ecu and have continuity however cannot seem to trace the wire for pin 1 ( the yellow and black wire)

 

[Fraz]

Ok...

Ive managed to trace the wires back to the ecu as follows -

Pin 1 - Fuse 34
pin 2 - 109
pin 3 - 101

This is by trial and error and all have continuity from the sensor plug to the ecu.

Im at a loss now...

 

[Muttley]

I'll repeat here what I put in the PM reply:

Pin 3 goes to pin 101 on the ECU connector. Pin 3 is the one by the rounded side of the connector
Pin 2 as already noted goes to pin 109.
Pin 1 goes to fuse 34, which should have battery voltage on it when the ignition is switched on. Pin 1 is the one by the flat end of the connector.

If you only have 6-7V between 1 and 3 then something is wrong with your power supply. Check fuse 34 and the wiring to pin 1. The wire should be yellow/black if the diagram I'm looking at is correct. Fuse 34 feeds several other sensors and controls (the N18, N75 and N239 solenoid valves, the MAF, and so on) so you may have to check if one of the other components is dragging the live voltage down.


I notice you said pin 102 above, not 101. Pin 102 is one of the feeds from the engine speed sensor, not the camshaft sensor.

 

[Fraz]

Now edited because Im an idiot and couldnt count...

 

[jamescupra1]

Has this been resolved as my sensor has gone and cannot be arsed with trial and error lol