Thanks for the additinal info Migbro, makes sense. Sounds like the plug w/ o-ring in the hub is simply for a clearance hole for manufacture so the .040" diameter passage can be drilled. Being able to access and clean the hole and then re-insert the plug with a new o-ring is a much cheaper alternative than many have taken and avoids the need to lock the cams.

I have to agree, the small diameter hole would not be forgiving of sludge build-up or crud suspended in the oil making its way to the small diameter passage, Aisin didn't develop their design for the real world. And what's with the silly head screws used on the assembly?

 

No, it's not there for that reason. The VVT hub contains a locking mechanism that holds the rotor in a fixed position versus the stator. The locking piston is under the hole plug and the function of the .040" diameter passage is to bleed off oil pressure from one side of the locking piston. The passage is small to control the flow rate of the oil through the passage but it's therefore also easily blocked by dirty oil and crud.

When the .040" diameter passage is blocked there is no oil flow through the passage, the locking piston can not move and the VVT hub remains locked which throws the P0015 code.

If you try this let us know the result.

When you pull the hole plug out there is a small spring under it - do not let it fly. Pull it out of the hole to allow access to the .040" diameter passage. Don't forget to replace it.

The .040" diameter passage is hard to see but when you find it you need to push a piece of wire into it no more than about 3/4" - maybe a little less - to clear it.

You may want to buy three new machine screws to replace the three you remove using vice grips or whatever. The thread is M6-1.0. You will also need a metric o-ring 8.5mm x 2.0mm to replace the old, hard one on the hole plug.

 

Sounds like a Sunday project. Will have to locate the small items. I will run some seafoam before an oil change to minimize the chance of a replug after cleaning. Thanks.

 

Did you ever resolve your issue with the CEL???

 

Are you still trying to figure out your code? That is what sucks about the VVT system. You don't know what to replace as there are 3 parts that could be bad and cause the same CEL. The normal routine is to replace the Cam Position Sensor, then the Solenoid, then the VVT gear hub. Each time testing to see if the code returns. Unless you can find someone with known working parts to test (maybe a junkyard vehicle?).

 

I have never seen it be a bad cam position sensor. I would start with the reset valve (assuming the oil is clean and full)

 

I've given up on trying to address the P0015 on my vehicle. I replaced the VVT two years ago and that did the trick up until 3 months ago. The code then came back RIGHT AFTER I replaced the sparkplugs (coincidence, I just don't know) so I replaced the Solenoid. No dice. I then replaced the ignition wiring harness (it was in brutal shape), no dice. I then changed the oil and used synthetic for the first time ever (not sure that will turn out to be a good idea) and that kept the code at bay for a good 6 weeks. Now it's back. I'd gladly replaced the cam position sensor but unless anyone can confirm that this has corrected the issue successfully I don't think that will do the job. The VVT system on this vehicle is ridiculously poor.

 

I have a 2001 S40 with 190,000 miles and the persistent P0015 problem. I've had everything replaced (sensor, solenoid, VVT) but it always comes back. I only think about it when I need to pass inspection. Usually an oil change right before the inspection does the trick. I'm going to do Seafoam this year and see if that helps.

I had to replace my MAF (Mass Air Flow) sensor last week as the car was stalling occasionally while in drive. Since the fix, the P0102 (for MAF) and P0015 codes have gone away. Could there be a connection between the MAF and the P0015 code? Or is this just a coincidence?