99-00 V/S/C 70 VVT solenoid question (Part 2)

Post by **scot850** » 13 Aug 2023, 19:52

I have several used VVT solenoids in the stash. Is there anyway to test these work?

Can I power it up with a 12V power supply with a ground and power connected? I think I may go and pull a connector plug and pig-tail to make testing easier. If I can do this in anyway, then I may look at making a simple test system to test at the junkyard.

Thanks.

Neil.

Post by **abscate** » 14 Aug 2023, 05:59

Not really. The resistance test can confirm continuity only ( if it’s -open circuit it’s dead) but this is a 200 Hz modulated solenoid so it has to work well under complex signals. I would pull one from a wrecked car with 95% confidence it would work

New price is $250 for reference

Post by **scot850** » 14 Aug 2023, 08:31

Thanks Abscate. Had hoped to be able to try to power it just to check the solenoid kicked, might try it anyway and cut a pigtail next time at the junkyard to see what happens!

I think I have 3 Turbo Exhaust, a 04 C70 with the later P2 style which is also an exhaust, and now a P80 NA intake as well. I see like your info on the water pump date code cast stamping, it looks like the VVT valves have the same. After cleaning, they are coded 98/99/03/11. So unless they were all bad (I will do a continuity test) they don't appear to be a high frequency failure part then.

As I have (thankfully) not had an issue with a VVT valve, what are the symptoms of one going bad?

Neil.

Post by **abscate** » 14 Aug 2023, 18:49

You will code P0014 cam reset valve out of range. Cam flank angle will drive to -20 and stay there

Post by **FireFox31** » 14 Aug 2023, 20:56

abscate wrote: ↑14 Aug 2023, 05:59 I would pull one from a wrecked car with 95% confidence it would work

I'd edit this to say a used rebuilt one is 95% likely to work. The rebuilt solenoids have their electrical connector coming out at a 180 degree angle to the body and require a different wiring connector. The original ones have the connector coming straight out.

I had two intake solenoids fail on 2000 V70 NA cars. Replacing the VVT solenoid on both removed the codes.

On "the G70", it failed at 218k miles, seemingly after I swapped out my ABS module. It showed DTC code P1672 +5V Power Supply (because it didn't know the correct Volvo description) and VIDA showed ECM-640A. Resistance across the electrical pins was 78.2k ohms while a used one I had (thanks abscate) was 4.3 ohms.

On Geronimo, it failed at or before 352k miles, code appearing after I replaced the failed ETM. It showed DTC code P1671 CMP Actuator Performance Problem Or Signal Out Of Range. Resistance across the electrical pins was zero

This YouTube video shows testing the VVT off the car by applying 12V to hear the solenoid click.

More info than you require:
An MVS user reports that "Vida/Dice can perform a function test of the solenoid while somebody views it for movement." I tried neither of these tests. I was able to use VIDA to graph the desired and actual cam angle before and after solenoid replacement to see the failure and correction. My notes are not yet current so I don't have this info on hand. Both cars drove reasonably with these problems, though had other problems which this may have contributed to.

Post by **scot850** » 14 Aug 2023, 22:07

That is awesome info Firefox! Really helpful. I'll have a further read on the attached info you included. Many thanks.

Neil.

Post by **abscate** » 15 Aug 2023, 04:00

On a 1999 on with ME7 you can monitor cam flank angle to see if the solenoid is doing its job.

Gory details in the cam flank angle thread. The solenoid “ cam reset valve” only moves the cam about one cam tooth over its operating range, so you can’t see the changes with a timing light or the like , too easily

Post by **scot850** » 04 Sep 2023, 19:19

I finally found a pigtail for the older style VVT solenoids (the straight solenoid version and connector), and also one for the newer 180 degree connector.

I have 6 solenoids I have pulled from the junkyard, but did not know how to check them. Only thing was this thread and viewing a few YouTube videos.

With the connectors I tried a continuity test with my cheap electrical tester. First Exhaust one was bad. No continuity. Bummer. $25 down the tubes.

I then tested the 2 other older style ones. One gave a resistance value of 620 ohms, the other around 16-17 ohms.

Finally tested the 2 newer design versions. Bot of those were 7-8 ohms. Following a discussion with a friend, he told me a good VVT should be 3.7 ohms.

The only Intake VVT I had 99 date code (Old design) and it was again in the 16-17 ohm range.

So this would say that pulling units from a junkyard is a waste of time other than if you test them in the yard, or accept they are for emergencies if you get a hard fail.

I also saw an interesting video on a guy servicing a Volvo solenoid, but the difference was those had a flange and bolt you could use to separate the solenoid from the mechanical section. That made it easy to separate the solenoid to allow you to clean the valve unit.

Terrible video with no commentary:

The old style look like the solenoid is bonded to the mechanical body. So I guess they are not-serviceable. Haven't looked at the newer version to see if you can service them either.

I know I can hook them up to the power supply and see if they operate.

So the question, if the resistance increases, does that mean the VVT is slower to respond, but is the response a linear slowing or does it slow faster the higher it goes (like 4 ohms new, if it goes to 8 ohms is it half as fast to respond or what?).

Last question, the newer solenoids are rated at 3.7 ohms (these look like the same one used on the P2's) are the old ones the same and what is the 'good' operating range?

Thanks,

Neil.

Post by **FireFox31** » 04 Sep 2023, 23:42

I liked that video when I first watched it years ago. Fascinating to see the inside of the solenoid. I considered disassembling mine until the resistance values proved it dead.

Consider putting your spare solenoids into a car and driving with them for a few weeks. Monitor them with VIDA. Maybe they respond slowly, but if the car doesn't throw a code and gets the same gas mileage, they're likely "used but good". Sure cheaper than $200+ for a newly rebuilt one.

Post by **abscate** » 05 Sep 2023, 04:45

My experience with resistance values on modulated valves ( turbo, VVT, purge ) is that a range of values near spec will work. Open circuit is certainly dead, a valve with thousand s of Ohms resistance is likewise also dead.

Very few volvo specs have ranges, unfortuNately

The evap purge valve does but I have found 27 +- 10 Ohms works well on