Variable valve timing CVVT Solenoid

[terry_cunnane]

How do you chek the CVVT solenoid out? I've tried it directly on the battery and I can see a slider move forwards and then returning when I remove the power. If I reverse the polarity it does the same thing.

I had a read of this http://www.volvoclub.org.uk/tech/fue...VTfunction.pdf. Its says the valve can advance the cam timing, retard the timing and when it is in the corect position it can hold the timing at that setting. Surely this would imply a third middle setting to achieve this? Should I be able to see this "third" position when I test it on the battery?

[grass hopper]

hi Terry,are you having any running problems or fault codes ? if so there are modified gaskets for the vvt valve with a filter and there is possibly a software upgrade to allow for slight deviation in the vvt readings to stop the EMS light being lit.

[terry_cunnane]

Hi Grasshopper,
No driveability problems just two fault codes which I am told relate to the CVVT system. (P1132 and P0013).http://volvoforums.com/forum/archive...hp/t-7499.html and here http://www.ilexa.co.uk/forum/index.p...c,14363.0.html.

I've changed the oil and checked the cambelt timing. I've just cleaned the CVVT with spray brake cleaner (although it didn't seem sludged) and used the newer type gasket with the mesh filter in it. I'll run it now to see if the codes don't come back but I'm not hopeful!

I haven't investigated the cam position sensor yet. I don't know of a straightforward way to test this.

Terry

[grass hopper]

hi Terry,there was a software upgrade for this,had a couple of cars in for this problem,i'm not sure if its for your model year but worth contacting your volvo dealer before you go any further.

[terry_cunnane]

Hi Grasshopper

I phoned M R King, my nearest dealer. They told me that there is an ECM upgrade available that might relate to the problem. They would have to have it in to read the codes and assess the situation. (Unfortunately they are 40 min away)
Terry

[grass hopper]

HI TERRY,worth the trip,should fix your EMS light problem,allows a little "tolerance" of the vvt readings,plus many other settings will be calibrated for better performance and economy,let me know how you get on.

regards GRASS HOPPER.

[terry_cunnane]

Hi Grasshopper

I've cleared the fault codes since cleaning the CVVT solenoid. I'll run the car until they return and then see about going to M R King. I will post here when I've been. Thanks for your help.

Terry

[terry_cunnane]

I didn't make it to MR King but did make it to Wright's Volvo near Norwich.
They read the codes and told me to change the cvvt solenoid. I did that and the fault hasn't returned after 150 miles.
I guess that was it.

I did have to be very careful assemling the new electrical connector though. I'll do another thread about that.

[KBB]

Terry,

The CVVT solanoid is held in a particular position by a pulse width modulaton frequency (PWM). In essence the ECU will provide a very fast on off grounding signal and will reverse the current flow to move the solanoid bi directionaly. You need a scope meter to see the signal in operation. This system is fitted by a number of manafactures. Software up grades are available to improve the function of the CVVT. If a new solanoid and software up grade do not inmprove the situation the VVT unit will be at fault. The internal pistons loose the ability to retain oil pressure bleed down and prevent accurate CVVT operation

[terry_cunnane]

Thanks KBB,

I always like to know technical stuff like that.
If problems return perhaps I should check with my dealer about a software upgrade. The Independent Volvo specialist (Wright's of Norwich) weren't aware of anything though they did say they would investigate. I must ring them to see if they found out anything.

Terry