Engine Light on - CPC Solenoid

Hi John,

Never heard of CPC solenoid, if the car is an automatic, it is possible he said "duty C solenoid".

This lives in the bottom of auto gearbox and is accessed by draining off the auto box fluid & removing the auto box oil pan and is a relatively cheap part.

(If my memory serves me well it is used to control power output to the rear axle, if it has failed then the car is running as a FWD rather than AWD"

Thanks for your response The issue is the car needs an inspection sticker which I can't get if the engine light is on! The 94 Legacy is a FWD and another response suggests that the solenoid is near the air intake. But if anyone has more detailed info ...would appreciate.

Could this be part of the vapor recovery carbon canister dealie? Sometimes there is just a broken plastic piece on some cars that will throw a code. Of course there could be a legitimate problem with a valve in that system too. justa guess

Carl

John Gibs>

Carl, I think that's it. My 2001 Forester's service manual uses the term "CPC valve" to refer to the "Canister purge control solenoid valve" or just "purge control solenoid valve":

"The purge control solenoid valve is controlled by the ECM and provides optimal purge control according to the engine condition . The signal from the fuel temperature sensor and fuel level sensor installed in the fuel tank is also used for this control."

"The purge control solenoid valve is on the evaporation line between canister and throttle body. It is installed at the under side of intake manifold."

Also check to be sure that your fuel tank cap is screwed on tightly. A loose fuel cap can cause an improper fuel tank pressure to show up and turn on the Check Engine light.

Wayne

provides

The purge control solenoid sounds like the problem. I have a 92 legacy that gives me an intermittent check engine light with the same problem. The 94 legacy also uses the OBD I diagnostics so it is quite easy to check yourself to verify. Under the hood you should be able to easily identify the green test connector just up from the hood release latch. Just connect the two green connectors (sometimes it could be black) and turn on the ignition (dont start the car). The check engine light will start blinking. You are looking for code 35 (3 long flashes, 5 short flashes).

Moving on, the purge solenoid is under the left hand side intake menifold when looking at the engine with the hood up. The part itself is rather small, a little over an 1.5 inches. It is a pain to get but does not require the car to be jacked up. These things cost about $100 to buy and replace yourself. Good luck

John,

Here is some info on this problem.