S60 T5 P0026 and P0016 Errors

[mikestr]

Hi everyone. I know that this general subject has been discussed here many times, but since each case is a little different I'm hoping that the details in this one spark some response from alert and knowledgeable members.

Recently my 2007 S60 T5 with 185K miles began showing a CEL and P0026 error--Intake Valve Solenoid. This occurred after some weird starts where the starter didn't catch right away; on a second attempt it would, but I'd get the error. The car seemed to idle and run fine. (I've since replaced the ignition switch.) After clearing the code it would only return if there was a difficult start. But later the idling became very rough and when cold took a lot of cranking. This is when the P0026 error ceased and the P0016 error began--camshaft position sensor. Once at driving speed performance seemed normal-ish, but perhaps with slightly less power. I replaced the camshaft position sensor. The car seems to have more power now but the rough idling and P0016 error have recurred, and consistently recurs after clearing the code and restarting. Wiring to the sensor looks OK. Timing belt is tight. Slight amount of old oil on the edge from a long-ago incident when an old fill cap gasket went bad, but otherwise teeth on belt and pulleys are dry.

What easy checks should I next perform before throwing myself on the mercy of the Volvo dealer? Should I pull the VVT solenoid unit and check for dirt or other crud? I have a spare I bought at the dealer's, but I don't want to install it merely for a test as it is costly and can be returned if I don't break open the bag. Please advise.

Thanks,

Mike

[jonesg]

Hi everyone. I know that this general subject has been discussed here many times, but since each case is a little different I'm hoping that the details in this one spark some response from alert and knowledgeable members.

Recently my 2007 S60 T5 with 185K miles began showing a CEL and P0026 error--Intake Valve Solenoid. This occurred after some weird starts where the starter didn't catch right away; on a second attempt it would, but I'd get the error. The car seemed to idle and run fine. (I've since replaced the ignition switch.) After clearing the code it would only return if there was a difficult start. But later the idling became very rough and when cold took a lot of cranking. This is when the P0026 error ceased and the P0016 error began--camshaft position sensor. Once at driving speed performance seemed normal-ish, but perhaps with slightly less power. I replaced the camshaft position sensor. The car seems to have more power now but the rough idling and P0016 error have recurred, and consistently recurs after clearing the code and restarting. Wiring to the sensor looks OK. Timing belt is tight. Slight amount of old oil on the edge from a long-ago incident when an old fill cap gasket went bad, but otherwise teeth on belt and pulleys are dry.

What easy checks should I next perform before throwing myself on the mercy of the Volvo dealer? Should I pull the VVT solenoid unit and check for dirt or other crud? I have a spare I bought at the dealer's, but I don't want to install it merely for a test as it is costly and can be returned if I don't break open the bag. Please advise.

Thanks,

Mike

you probably need a cvvt gasket if you pull it off. Backprobe instead.
Theres a screen in the base of the cvvt solenoid that can clog which might cause response lag.
Vida has a running test that will show if there is any response lag from cvvt.
When I ran the test it listed slow response and possible causes being oil pickup and seals in the oil pan or improper viscosity of engine oil. I did an oil / filter change and the code went away.

If you ever get to a pick and pull its a good idea to snip all the various connectors to the sensors.
Makes it easier to run tests than backprobing.

[mikestr]

Thanks so much for your response. Sorry to be such a rube, but what do you mean by "back probing'? I do have a new gasket, however; I bought it with the new unit (which I may or may not need, depending on test results).

[mikestr]

Ah--OK, I looked it up and understand. I assume I'm looking for a signal. Which pin and what voltage should I be looking for?

[jonesg]

Ah--OK, I looked it up and understand. I assume I'm looking for a signal. Which pin and what voltage should I be looking for?

Its safer to test ohms .Its just a coil, see this.

[mikestr]

Ok, I saw the video--thanks for that. The inference is that an open in the coil is the mode of failure--super-easy to check. I've also read that there is a screen somewhere that could be clogged, interfering with the oil flow and thus the functioning of the VVT system. In the event that the coil is OK, should I be checking this other part, or am I simply getting ahead of myself?

[jonesg]

Ok, I saw the video--thanks for that. The inference is that an open in the coil is the mode of failure--super-easy to check. I've also read that there is a screen somewhere that could be clogged, interfering with the oil flow and thus the functioning of the VVT system. In the event that the coil is OK, should I be checking this other part, or am I simply getting ahead of myself?

I would pull it off, its easier to deal with when its on the table, everything will be self evident.

[mikestr]

Will do--thanks again.

[mikestr]

I pulled the VVT solenoid unit and found that it was bad--no continuity. Popped in the new one and all is well. Thanks for the guidance. I feel slightly embarrassed at not having thought this through a bit more before taking your time. These solenoid units are extremely simple in design and indeed all is self-evident once the unit is removed. They don't even have a switch, just a plunger and coil--two pins only. Duh!

Thanks again.

[jonesg]

Good job.
Now I can go back to staring out the window.