Code P2646

Hello, I'm Danny.

Normally with any type of valve train code as you stated you would hear loud noises coming from the valve train due to oil starvation. I've attached information below for that particular code. Hope this helps and thanks for using 2CarPros.

Hello again.

I've also attached below the instructions on how to change the intake rocker arm solenoid valve 1.Hope this helps and thanks again for using 2CarPros.

Danny-

Following up on my previous questions. I have changed the solenoid and oil switch. There are no loud noises from engine. Oil is at level had an oil change. Car runs excellent. Engine light still on? Any ideas what's going on? Could it be electrical-Harness? I'm lost! Any suggestions in how to proceed?

Good afternoon,

To add to Danny post, I have attached the correction for this code for you to view. There are issues with debris in the cover that causes this code. I attached pictures for you.

Roy

Correction
If diagnostic procedures in service information do not resolve the vehicle's concern, remove and inspect the intake rocker arm oil control valve for missing components.

See illustrations below for items #1 being missing.

If any of the components are missing, replace the intake rocker arm oil control valve and camshaft cover.

The camshaft cover must be replaced because the components become lodged in the camshaft cover oil passages and can not be removed.

If the intake rocker arm oil control valve is not missing any components, only replace the intake rocker arm oil control valve.

Note: If a previous rocker arm control solenoid came apart and pieces are stuck in the cam cover passages, this can cause any of the concerns to happen even when a new rocker arm control solenoid is installed.

Evaluate the vehicle thoroughly after repairs to verify the concern(s) are corrected.

This is a good valve with components still in place.

I'm looking for the GM part number for an Intake Rocker arm oil control valve and cam shaft cover. I don't see part number posted? Thank-you

You have 3 requests open. I am going to contact the Admin to combine them for you. You can just reply to any of the posts I have responded to.

Still waiting for an answer to your last request.

Roy

I didnt get information with GM part number?

I just attached it again to this post for you.

Roy

Thanks.

You are welcome.

Always glad to help.

Roy

Are there any car symptoms for a bad intake rocker arm oil control valve?

Also, P2646 diagnostic result said intake rocker actuator stuck on? Do you think this is the right part?

I sent you all the information on the code and the recommended procedure for the repair. You need to follow the procedure I posted and check to see if the parts came out of the old one.

Roy

I looked at the info. I'm not getting any car symptoms as stated on the info sheet car runs very well . idling is good.

But you have the code and the reason for the code will be found with the checks that need to be performed. You may not notice any difference in the running but the PCM does see it not responding correctly to its commands.

Roy

I took my vehicle to a mechanic. This is what he did: checked trouble codes: p0089 and p2646. Checked data stream. Check for TSB. Checked quality of oil and level. Checked control valve timing and oil pressure. Checked engine oil pressure. Tested circuits and wiring to intake rocker arm solenoid. Removed and inspected rocker arm for damage. Reassembled and cleared trouble codes. Ran car for an hour idle position. Road test. Everything is okay. Engine light is off, hasn't been on. No parts changed. What do you think tripped the codes?

You may have had dirt in the oil passages. It is possible but you will find out in time.

Roy

I had an oil change today. Oil plug was stripped. I changed it. Do you think this caused engine light on? Dirt got in?

No, I do not. It is much more than that.

Roy

My light hasn't gone on. Engine runs great. Everything was checked as outlined to this mystery. if any one else that owns a Malibu-2015. i would like to know what they encountered? I would let General Motors know if this is an issue with that code?

I gave you all the information on the code, recommended repairs and my own opinion.

What exactly have you done? You never listed what was done?

Roy

Solenoid and oil switch changed. Various tests were done as outlined in previous emails.

So you did not follow the TSB recommended procedure.

Until the proper repair is made, the light will remain on.

Roy

The light is off. Your recommendation wasn't correct. If you read what my mechanic did and tested? Are you a licensed mechanic?

I am a licensed technician with 50 years of experience and nationally recognized from ASE.

You can take my recommendations or not, your call. You asked for my help and I gave you the correct information not the incorrect information.

If your guy is so good, why is the light still on?

Roy

The light is off. I have stated it a few times.

For now. It takes a while before the issue may return.

We will see over time. Hopefully it does stay off for you.

Roy

Follow up: Would you know the GM part code for an intake rocker arm oil control valve an cam shaft cover?

Hello again.

I posted the information for you in a previous post.

Did you not get that information with the part number?

Roy

I vehicle diagnosed. Code P2646 came up. Change VVT solenoid. Engine light still on same code will not clear. Car runs great. Any suggestions on what is going on or how to fix?

Hello my name is Dave.

First things we need to make sure of is that that is the only code and that you have proper oil in good condition, at the proper level and that you have good oil pressure. The reason for this is that the solenoid controls oil flow to the actuator and if the pressure and oil isn't correct then it will set this code.

Here is a link to our tutorial on checking for high oil pressure however the process also applies to low oil pressure:

https://www.2carpros.com/articles/high-oil-pressure

Either low or high oil pressure could adversely affect the solenoid. Your pressure should be between 20 and 28 PSI at idle (700 rpm) once the engine is at operating temperature. Please let us know what you find and thank you for using 2CarPros!

Only code i am getting is P2646. I did change solenoid and changed oil. The engine has went off and hasn't come on for 3 days now. If it comes on again its most likely the oil switch. Thanks

Just want to add an observation on this one. I had one not to long ago that the rocker was damaged so here is the testing to follow in case it does come back on. Pay particular attention to the Circuit/System Testing. Thanks

I changed the VVT Solenoid. Can the engine light stay on then go off after so many miles? Code was P2646. Had it diagnosed three times?

P2646 is a type A code. That means it takes one failure to set, it also means it will clear as soon as the system sees the fault is repaired. If you replaced the solenoid and it still shows the code you still have a problem. That code can be set by low oil or using the wrong oil as well as if sludge blocks the oil passage. Now that you have changed the solenoid I would probably do an oil and filter change and be sure to use the correct oil.
Beyond that you will want to remove the valve cover to verify that none of the rocker arms are stuck so the pins cannot extend as the code shows the system is locked in the off position.