Charge pressure positioner conector clip

I think I fixed my turbo limp home problem.

tl;dr In the end, I think it was the tiny little plastic clip on the electrical connector for the "Charge pressure positioner"



I was seeing code P1470, "Charge pressure control valve - Charge pressure too low", along with LHM limp home mode, no turbo, won't rev above 3000, gutless, and sprintshift in manual mode only.

Took it to my mechanic, who reported turbo bypass actuator mechanism moved ok, vacuum was good, and turbo hoses and intercooler looked in good order, should be fine. Put everything back together again and charged me, but as soon as I put my foot down it happened again.

I know most mechanics are not the best with electronics, so I attempted to do the next line on the diag sheet myself. Test the wiring between the computer and the charge pressure positioner.

Turns out it's a pain to get to, you have to take out the window washer water bottle, then the air cleaner assembly top AND bottom. It's under that. Once there I was hoping to find some obviously corroded connecters or warn wiring, but it looked perfect. meaning it must be the turbo.

So I gave the end a little squirt with contact cleaner just in case, and started to put it together. Then I discovered when wet/clean (with the contact cleaner) the connecter would just fall apart again. The clip to hold the electrical connector on is a rocker arrangement with a loop on one end and a thumb press area on the other, about 10mm long and 4 wide. Obviously you press down on one end and the loop end lifts over the catch so you can disconnect it. But the rocker had no spring in it! No matter how hard you pressed the plug in, the latch would not lock closed. Resulting in the plug being easy to unplug, and I think it was probably falling open before.

With a tiny flat screwdriver, I managed to get the clip loop end pressed down and it latched with a click and seems quite secure. The thumb press end is now sticking above the edge of the case, which it definitely wasn't doing before.

Anyhow, it now pulls hard up to 4 and a half grand and has bucket loads of power. Situation normal for a lightly loaded 2.7L turbo. I went for a 30 min drive, and tested as much as I could, but we'll see if the problem reoccurs in the next few weeks.

Thankyou for the excellent photos in this thread, showing me what I was looking for.
https://sprinter-source.com/forums/showthread.php?t=23067

And also for this thread showing me how to work the connecters on my computer. (I also hit them with contact cleaner, but don't think that was the problem)
https://sprinter-source.com/forums/showthread.php?p=295225

Nathan,
What's the tachometer redline on your 2004 2.7 liter I5?? 416 Sprinter?
Every 2.7 liter I5 (OM-612/OM-647 has a normal redline RPM of 4,000.
The rev limiter normally kicks in @ 4200-4300?
Also, unless something is very different with the AUS Spec Sprinters, your Sprinter OM-647 makes
it's best torque/horsepower in the 2800-3200 RPM range.
Spinning it > ~3600 RPM doesn't get you anything.
Roger

I know, I don't drive around that high as a matter of course, my normal hill climbing go to is about 3000rpm, just as you suggest. And on the flat I'll only change to keep it above 2000. However, with no turbo, 3000 rpm is not making peak torque, I'd guess about half power, if that. And forget about revving higher.

It was more to point out that it was now working properly, producing the expected power over the full rev range.

Nice work. Is that the solenoid behind the front right headlight? Do you know the fifference between Y87 and B87? I am wondering where the other one is located. I found the one near my air box behind the headlight (remove front grille and headlight).
Glad to hear you found the problem. i am still hunting P1470. Thanks