LNF: can anything in a tune cause P0299, turbocharger under boost?
Been running into this issue only after I run through one gear and partially into a second boosted gear. will get a P0299 code pretty consistently. But never when I am just going through one gear. I can make it through a 4th gear pull of 7.5 seconds without it. But a quick 2nd gear pull, and then into 3rd, the code will happen at about 5.5 seconds total boosted time, and only about 5500 rpm into 3rd.
Has anyone seen anything in a tune that might cause this?
Attached is the log (happens just after the 20 minute mark where there is a two gear pull that ends suddenly). It then goes into limp mode.
Everything to me looks good in the logs and I don't see any reason it would trigger that code. I know it is often mechanical and a boost leak, but AFR is on target and trims are good, so I don't think it is of a boost leak nature. I have seen a comment or two before about a tune somehow possibly causing this, but I have no idea how it could.
Car otherwise seems to run perfect and strong (all stock parts btw).
Let me know your thoughts if the tune could be involved.
Thanks Mike. So check boost solenoid and the other solenoid that controls the BPV (which I think would cause this if it spontaneously opened up).
Just for learning, what in the screen shot might show a clutch slipping?
As a side note, I put the GMS1 tune back on and made a full pass through 2nd and 3rd gear twice without throwing the code. Weather was different, and boost is much lower in that, so maybe that puts less strain on the solenoids not having to work as hard. In my tune the boos solenoid is commanded to hold 85-97% through the power band, whereas the GMS1 tune is only in the 70's % range for the runs. Maybe it is getting weak and just can't maintain the higher duty cycle that the higher boost requires?
Possibly. It could be in the tune, but off the top of my head I couldn't think of what, and I didn't pull it up to look at it. I would lean towards the solenoids but I could be wrong.
The clutch slip shows by the spike in rpm you have. Notice how the speed stays as a flat curve? Your 1st gear pull the rpms spike, 2nd gear pull it spikes, and in 3rd gear it stays parallel with speed.
If you want to test clutch slippage, start at 35mph and do a 2nd gear pull. I would only do it once, or just take my word that you have clutch slippage.
Just to follow and put closure to it, it did not turn out to be the tune, but was a physical problem. End tank on the IC was cracked, which shortly afterward popped completely to make it completely obvious.
It's OK. I can get it to slip at low rpm in 5th gear (under 3500 rpm), but it is holding in 4th at any rpm as long as I keep boost in 4th to 22-23psi. I have gotten it to slip at low rpm in 4th also but only when boost was 24-25 psi and it was colder outiside. I have used torque by rpm to limit boost for 4th and 5th gear compared to 3rd (3rd is set for 23-23.5psi with no torque by rpm limts). In 5th I keep it to 19-20psi until 3500 rpm where I let it ramp up slowly after that. Third holds 23-23.5psi at any rpm without slipping at all.
I think I just saw in my first screen shot what appeared to be clutch slip to you. I think I had downshifted from 3rd back into 2nd gear and tapped the gas to rev match a little. I did that just before the boosted run through 2nd and 3rd gear that is shown. So the rpm jumps up with no change in speed appearing like a clutch slip.
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