Check Engine Light (Code P2646) - solved by replacing VTEC solenoid assembly
About 8 months ago my Element EX (with about 160k miles) suddenly lost power on the highway while traveling up a steep hill. The auto trans had just downshifted, RPMs climbed higher - I was cruising at around 65mph. It felt like a stall, but it did stumble a bit around 1k RMP and then regained power. I thought it was a fluke and then it happened again. Decided to cancel my trip and turn around for home before I got too far away.
I started looking into the problem but found there were several possible causes, but the main symptoms are: hesitation or stalling around or above 3k RPM, and also the check engine code P2646.
In the meantime, I cleared the code, changed my oil (dirty oil is one possible cause) and started driving it around for short trips. In the next 4 months it never happened again so I assumed the issue was resolved by changing the oil. Then about 4 months ago it happened again…and again…and again. At some point, my wife refused to be in that car with me until I found and positively fixed the problem.
After a bunch more research, I became convinced the problem was with my VTEC Solenoid Assembly. I thought about rebuilding for the common problem, but fully rebuilt units are pretty inexpensive so I just bought a whole new replacement assembly for under $40 on Amazon. Here’s a link to the one I bought:
This solenoid assembly has 3 major components: an oil pressure sensor (with dedicated wiring harness), a solenoid (also with its own dedicated separate wiring harness), and a screen and gasket piece. Any one of these three major pieces can cause the problem.
After the new unit arrived, I set out to remove the old unit. It’s on the backside of the engine so you are working blind with the tools, but luckily you don’t have to remove any other parts of the engine to gain access. The hardest part was the fact that the 3 bolts are angled toward the ground by about 15 degrees…and so my assumption that they were parallel to the ground was causing me to slip the wrench a bunch when trying to unbolt them. After getting the old unit out, it was obvious my problem was the screen. It was super clogged.
Putting the new unit back in went pretty smooth. I did have to create some clearance between the unit and the protective shroud to make room for the wiring harness pigtail connecting to the oil pressure sensor piece, but that shroud was soft and easily bent to make the clearance. The post photo shows the difference between stock part (left) and aftermarket part (right) - the wiring harness for the oil pressure sensor is the lower left connector in the photo.
2-days after getting it installed, and after a bunch of proving drives, I took the vehicle on a 400 mile road trip without issue. Problem solved.
This YouTube video was SUPER-HELPFUL. I followed exactly what this guy did.
I kept my old unit. Definitely keep your old unit if you do this swap. I’m going to get a new screen and gasket and rebuild my old one to keep as a ready spare in case I need to do this again some day.
Hope this helps anyone experiencing the same issues.
Add comment