Thread: Fault code P2263-22: Turbo System

I had the same code with intermittant Restricted Performance events, usually on a slight incline with CC set at highway speed. The turbo bypass valve appeared to be working fine, but monitoring the signal from the valve on the bench showed occasional bad output to the ECU. In the end a new valve fixed the problem ($$$$$). I was also getting the code P004C(77)B.

Then a month later I got Restricted Performance due to a sticky actuator on the secondary turbo with code P004C(77)A, 'exercising' the valve and an Italian tune up with Nulon Diesel turbo cleaner fuel additive appears to have fixed the issue, for now......

It appears the previous owner drove quite sedately

Originally Posted by Anton

Hi Eric, unfortunately this is not the case. The primary turbo is a VNT turbo controlled with electronic stepper motor, no vacuum solenoid involved. The secondary turbo is vacuum operated. Hence why I'm failing to understand how the vacuum lines affect any turbo function under 2500RPM as the secondary turbo only blends in at this RPM and above. Don't get me wrong, I'm not saying the vacuum system can't be the cause of P2263-22, I'm just trying to understand how if my DTC's indicate under 2500RPM and almost no load every time.
Regards,

The turbo itself isn't vac controlled, but the rest of the system relies on it. I think the isolation valve or something.

I had the same issue not long ago.. Can't remember what I did now.. But it wasn't much.. no money spent

Originally Posted by josh.huber

The turbo itself isn't vac controlled, but the rest of the system relies on it. I think the isolation valve or something.

I had the same issue not long ago.. Can't remember what I did now.. But it wasn't much.. no money spent

I'm also of the opinion that the route cause isn't anything major like secondary turbo etc, doesn't add up. The isolation valve is indeed controlled by vacuum but from my understanding (and I could be wrong) the valve opens the passage for air flow from the secondary turbo at 2500RPM thus blending in with the primary. This means under 2500RPM the spring tension of the isolation valve keep it closed, not vacuum. My thoughts, if there was a vacuum leak this should only trigger a DTC associated with the secondary turbo in play (over 2500RPM), low boost, leaking boost, MAF - Boost sensor correlation etc. I'm getting none of these.
Back to the drawing board.

I think they start blending earlier to start the turbo spooling, if I think hard enough I think I free'd up all the linkages that I could see and I think it was the EGR in the end.

Originally Posted by Anton

Hi Eric, unfortunately this is not the case. The primary turbo is a VNT turbo controlled with electronic stepper motor, no vacuum solenoid involved. The secondary turbo is vacuum operated. Hence why I'm failing to understand how the vacuum lines affect any turbo function under 2500RPM as the secondary turbo only blends in at this RPM and above. Don't get me wrong, I'm not saying the vacuum system can't be the cause of P2263-22, I'm just trying to understand how if my DTC's indicate under 2500RPM and almost no load every time.
Regards,

Correct, it's the air valve I meant that actuates the secondary turbocharger. The ait bslve can get stuck or not close properly.i took mine out and stripped it and cleaned it out once, then ended up having it replaced under warranty.