CPC Valve Duty Ratio (%)

[west_minist]

Anyone know what this is?

[crispyduck]

Anyone know what this is?

It is the Canister Purge Control (CPC) solenoid valve duty ratio.

The charcoal carbon canister is part of the vehicle's Evaporative Emission Control System and is purged by a vacuum operated purge valve. The ECM controls vacuum to this valve through the Canister Purge Solenoid. This data field displays the percentage of time the canister is being purged over a predetermined time interval. On most vehicles the purge solenoid is energized to inhibit purging and de-energized to permit purging of the charcoal canister. This solenoid is energized during a cold engine condition and is de-energized after warm-up when the engine is above a specified RPM. Canister purge allows collected fuel vapors in the canister to be drawn into the intake manifold for burning. Canister purge on some vehicles is controlled through a combined EFE/EGR/Canister Purge solenoid unit. Information source: Project Transam

In summary, it appears this is part of the emmision control system thus not an interesting parameter to be tuning - no performance gain!

-Steve.

[west_minist]

All sounds wonderful, but how does nit affect the engine?

Can it be fault?

[haha]

My ECU is throwing a code for this
P0485 or P0458 - I forget which one
but my rom doesnt allow me to "disable" it
how do I go about solving this ?
Help !

[Freon]

It won't hurt anything if it doesn't work right. It is just evaporative emissions stuff.

west: Not sure how to explain how it does not affect engine operation. I don't think the burden of proof is to explain how something does not affect engine operation.

crispy: why can't you disable it? And you really need to know exactly which code you're getting.

[crispyduck]

I think Freon means 'haha'

[west_minist]

It won't hurt anything if it doesn't work right. It is just evaporative emissions stuff.

west: Not sure how to explain how it does not affect engine operation. I don't think the burden of proof is to explain how something does not affect engine operation.

crispy: why can't you disable it? And you really need to know exactly which code you're getting.

Thanks Freon and everyone.

[thejean]

Is it normal for a cpc valve duty ratio to ossicllate if te AFRs are oscillating?

[Freon]

I don't think the two are necessarily connected.

[Dougnutz]

I'm pretty sure Freon is right about them not being related.

Most cars cycle the cpc during cruise conditions and it normally oscillates when it is on.