2001 NA P0300 rough idle ( CVVT SOLENOID BAD, NO CODES!!) Topic is solved

[George Dunham]

Just installed cvvt solenoid. Problem solved! Who wooda guessed?

[abscate]

You usually get a code for the CVVT out of range when these go do your follow up is great info, thanks!!

[precopster]

Put a totally faulty CVVT solenoid from an XC70 (that would code within a half block drive) in to my 2001 T5 and my car basically ran like crap and also had a high idle speed of 900 rpm.

Only thing is this solenoid was faulty and it refused to make my T5 produce a CEL. Once replaced idle dropped to normal (sub 700rpm) and car now runs like a dream.

Must be something to do with engine firmware version. Some cars are going to give the diagnostic team a hard time so they can earn their money.

[abscate]

Trying to think of an alternate way to diagnose this, and failing.

Is there a trigger for a timing light that you could observe the cams somehow ??

[precopster]

Vida has expected and actual values for CVVT in live data so even if it doesn't code you can still see if they are acting properly.

[mrbrian200]

You cannot test this solenoid this way. It is a frequency modulated solenoid, not an off/on switch.

It was my understanding the oil pressure was regulated in the VVT via this solenoid being driven by a PWM signal like an AT shift solenoid: with DC current the plunger should make some sort of click or tick. No?

[abscate]

I think that's right but they commonly fail by being sluggish to respond, not a digital 1/0 failure.

I think if you suspect a solenoid you either swap or use VIDA to diagnose

[hyperiongate]

so what tests and what expected outputs for the cvvt. I have Vida/Dice and it doesn't flag anything.
I have the same issue.