ECM-6440 CVVT reset valve?

[dcarlson12]

99 S80 T6. Has approx. 130,000 miles and timing belt was renewed at just under 100,000 miles. Use Mobil 1 synthetic.
Had the car off the road/stored for about a year. Used to start it and run it for about 20 minutes every month or sooner to keep things lubricated and the battery charged.
Near the end of the year just before I put it back on the road, CEL came on and I scanned with BSR PPC diagnostic scanner. DTC ECM-644A or ECM-6440 came up. I say 'or' because I actually think it was originally ECM-644A but I cleared it and lost the paper where I had written the code.
I again had the car off the road recently while repairing the 'lava' lamp syndrome. This week I replaced the alarm siren and after putting it back on the road this week, I used the BSR PPC unit to reset the codes and found the ECM-6440 code which relates to CVVT reset valve.
There are no apparent issues with engine performance and the idle is steady.
VADIS says the symptoms of a bad reset valve are poor/uneven? idle or poor performance.
Is it possible that the reset valve is just 'acting up' intermittently and the 'problem' will cure itself?
This is my third day of driving since resetting the DTC(s) and the CEL has not yet come on. So about 6 driving cycles and still no CEL.
It seems that there is no way to check to see if the reset valve is 'bad' or ????

[jimmy57]

I think the ECM 6440 is the code for open circuit to the valve. I would check contacts in connector and if it returns after connections are checked then replace the cvvt solenoid.

[dcarlson12]

Thks for the quick reply.
Is it necessary/beneficial or ??? to disconnect the negative battery terminal when unplugging/checking the connector?

Edit July 14: The ECM-6440 came back and also ECM-644A

Have not yet checked the connector. Would poor connection also cause 644A?

If not connector, is there much chance that one could just 'clean' the valve and bring it back to life? I see that the dealer says these are re-manufactured items when purchased as a part from them. i.e. they charge/refund a core fee

[dcarlson12]

`Cleaned`the connector and seems to have solved the problem. i.e. no DTC`s after driving about six driving cycles.
Thks Jimmy57!

[dcarlson12]

Well the codes have come back but I believe it is still likely just poor contact at the connector. I tried to lightly 'scrap' the surfaces of the contacts with a very small/thin file the last time but it would seem I didn't do a good enough job.
Is there a better way to 'clean' the connectors? i.e. possibly an electrical contact cleaner or ???? Would thin and fine sand paper do any good or harm if I could manage to get any into the contact points....?

[dcarlson12]

I used a product called Deoxit (http://store.caig.com/s.nl/it.A/id.1602 ... tegory=188) to clean the connector and valve connector. It seems to have worked, at least so far.

[dcarlson12]

ECM-644A came back again last week after I drove through a large puddle in drenching rain on the freeway. Perhaps it was just coincidental.
When I connected the BSR PPD diagnostics 'scanner/tool', I found a number of other codes had been set eg. something to do with steeling wheel module communication, door module communication, UEM communication. Reset the codes and then ran car for a short time. Code(s) did not reappear.
Wife went and filled the gas tank a couple days later and during our evening walk yesterday she just remembered that the Check Engine light came on. She forgot to tell me.
Reset the code after getting to work today. Will see if it reappears. Still have a feeling it is the connector but haven't figured a better way to clean it.
Because the other codes appeared after going through the 'deep' water at high speed, kind of think they were caused by water entering a connector. Just wonder if the CVVT reset valve goes 'through' a connector on the same wiring harness????
I guess I should be used to the frustration that this car gives to me but I am not....
Performance does not appear to be affected.