Dtc p0011

[68problemchild]

This is an L92 with a custom Cam and VVT.

Any ideas what the most likely cause of the above code is?

[68problemchild]

CAMSHAFT POSITION ”A” -TIMING OVER- ADVANCED OR SYSTEM PERFORMANCE (BANK 1)

Should I adjust???:

B7930
B7936
B7935

B7902
B7903
B7904

[68problemchild]

Adjust tables or commands for using the tables?

In this tune, I see mods for low and high barometric pressure but not medium. Perhaps the medium needs a tweak. Someone indicated the cam is always in a fully advanced position unless retarded by the tune?

Open to ANY ideas.....



One system, and the most widespread by far, is simple cam phasing. Instead of the camshaft and the crankshaft turning in perfect sync, cam phasers can rotate the camshaft several degrees in either direction. Most cam phasers are installed on just the intake camshaft, where it can rotate the cam back, or "retard" it, at low engine speeds letting the intake valve close early and giving the engine more torque off the line. As the engine speeds up, the phaser will rotate the cam forward, or "advance" it keeping the intake valve open longer during the piston's intake stroke so that it can more fully suck in an intake charge. In doing so, the cam phaser moves the engine's torque peak into the higher reaches of the tach, making the engine's torque curve broader than it would be in a traditional engine.

[Taz]

No one is jumping in here ….

Gen III guy - was able to assist a little with the transmission part of your swap - as a 4L70 is essentially Gen III based.

I know your VVT cam is an aftermarket grind. Are you using the stock cam phaser, or one that limits the amount of movement (like those offered by Mast, etc.) ?

If using a “limiting” style of cam phaser, try adjusting the parameters to match this component. I have never tuned a VVT engine - hopefully a Forum member with experience in this area will help out ….


Regards,
Taz

[68problemchild]

Thanks Taz. Its the stock phaser with a phaser limiter piece put into it, so it cannot over advance and cause damage.

The cam had built in timing advance of +5. Just not sure if that is what is causing the code. Geoff indicated he has gotten this code before with the setup and sets it to no mil.

Other reading has revealed possibility of: Debris in oil, low oil, wrong oil viscosity, stretched timing chain, timing off a tooth.

[Taz]

OK … just thinking out loud …

The OEM cam phaser allowed a certain amount of advance, which you have restricted mechanically. Wondering if the DTC is set when the ECM commands maximum cam advance, but this fails to occur due to the presence of the mechanical restrictor.

Try this …. calculate the percent of maximum currently available cam advance, compared to the original OEM value (ie. now 75% of the original amount).

Using the above 75% example … in B7930 (Cam Position ECT Multiplier) set any values that exceed 0.7500 to no more than 0.7500 (75%).

B7930 appears to restrict cam advance when the engine is cold and under light load.

Trying to think of way to make your mechanically restricted advance compatible with that commanded by the ECM.

Again, I have never tried this ….


Regards,
Taz

[68problemchild]

Will try. Thank you!

[68problemchild]

OK, capped the Cam tables at values no greater than 19 for advance. No code.

After a few more runs with no code, I will up it until it throws the code, then back it off a few. Very cool.

Keeping my fingers crossed.

VSS_DMA is also still spot on while VSS is off. Hope its reading VSS_DMA!

Interesting that this advance change also seems to have reduced the LT fuel trims a bit.

Thanks Taz!

[68problemchild]

Oops. Code is still there.

Any way to telll when its being thrown?