Diagnostic code 46
 

When I bought my FD the check engine light would come on after driving for a short period of time. The previous owner said it had been that way "for a while" The car has about 5k on engine rebuild (by Pineapple Racing) and stock turbos. Today I finally got around to checking into this and got a diagnostic code 46, which is related to the Charge Relief Solenoid/Valve. From what I understand this is a pressure relief for the 2nd turbo when the engine is below 2500 rpm. My question is two-fold....

1) What symptoms/damage will occur if this is not taken care of? My guess is loss of boost over 2500 rpm, but I'm not having that problem. At Least I don't think I am. If I am, HOLY SHIT!!!! This thing runs like a scalded dog, especially over 2500 rpm. If it's suppose to be faster.....HOLY SHIT!!!! Of course that depends on whether the open or closed condition of the valve is effected. If stuck closed I'm wondering if it would decrease my low-end power by causing increased pressure in the turbo housing, resulting in lower rotor speed. I don't have a boost gauge (yet) so I can't tell what my boost curve looks like. What I do now is below 2500 the car is pretty quick, but so was my 1st gen. Once the tach hits 2500 or so this thing is CRAZY fast!


2) Which should be replaced first, the solenoid or the valve? The valve looks pretty easy to get to, but the solenoid looks like it would be a bitch. Should I just replace both and be done with it?

Before anyone comes back with the "Just replace it with...." I appreciate the input, but for now I'm just looking to keep things stock. I've only had the car about 2 months and only put about 800 miles on it so I'm still learning how to drive it. It's already gotten away from me once on a wet left hand sweeper....$1800 damage when I did a 360 and kissed the curb. Why there was a curb there I have no idea...Murphy's Law I guess.

Anyway, any advice would be appreciated.

I can't believe nobody has anything to comment on this

Because your getting an electrical error code i beleive the problem is your solenoid or the electrical connection at that point . Now let me see what problems would it cause, mmmmmmmmmmmm i beleive that if that solenoid wasnt working then the bypass couldnt bypass the prespool air generated by the 2nd turbo causing the 2nd to stall or be really working its balls off because its blowing down a blocked pipe (the prespool actuator vents a little exaust to the 2nd turbo to start it spinning before 2nd transistion),, Would have thought it would lead to a bad drop between 1st and 2nd turbo maybe 10-5-10??

Just read my post and it dont make much sense,, ill explain,
The primary turbo spins generating full boost quickly from 1000rpm to 4500rpm, the ECU vents a little exaust during this period to start the spinning of the second turbo and vents the air pressure created through the charge relief valve. When the car hits the 4500rpm the releif valve closes and the charge control actuator opens letting the air from the secondary turbo be added to the first (so now you have 2 turbos blowing into the engine),, like i said in my original post i beleive if the valve doesnt open during prespool when the engine hits transistion period (4500rpm) you will get a large drop in boost 10-5-10

Well, have you followed the troubleshooting procedure on page F-58 of the factory service manual (FSM). You can download it for free from the stickied thread near the top. We can't look at your car for you!

And trying to troubleshoot anything with the turbo control system without having a boost gauge is nearly impossible. Get one ASAP, even if it's just a cheap mechanical one from the auto parts store that you hook to the upper intake manifold (UIM) only for testing. (I did this before I got real gauges.)

Funny, but I don't recall asking anyone to look at my car for me. Just looking for some helpful information from someone who may have experience with this subject since I am new to the FD world. I will, however, take your advice on the boost gauge.