My 2004 Accord EX 4 cylinder with 205,000+ miles just popped up CEL with P0443 code. Any advice on where to start troubleshooting? Do I do a vacuum leak test or start replacing parts? Fuel cap seems OK, but maybe I need to inspect closer. If need to replace parts and hoses, are there recommendations of what to do first (cheapest first?)?

Here is history of investigation so far:
- CEL came on 4-Jan'20 code was for P0443 Evaporative Emission System Purge Control Valve Circuit, and Evaporative Emission Control System Purge Control Valve Circuit Malfunction. Auto parts store said likely cause was bad Canister Purge Valve.
- likely separate issue, but at same time: car has been due for oil change and I had been putting it off, so Maint.Req. light was on. Last oil change was 9,000 miles prior.
+ 8-Jan oil light came on blinking... drove the 2-3 miles home, found oil was VERY low... but I've never had an issue with low oil. No leaks on driveway, so likely car is burning oil (new thing it seems).
+ changed oil once I got home... drained about 2qts... very dark oil. Oil like is now off... whew.
- 9-Jan CEL light turned off while dropping son off at school in morning, but within 15-30min it was back on
- I've been running with duct-tape around air intake hose (between air box and intake) which was cracked by oil-change guys.
- 11-Jan replaced air intake hose and air filter.
- also on 11-Jan did 9V batter test on Evap purge solenoid as seen in this vid ( ) at ~11:15, but with part still in car, just with connector disconnected. Power to solenoid causes clicking noise, so assume part is working properly.
- 13-Jan cleared codes at auto store, and CEL came back on, confirmed reading, but now with just one message with P0443: Evaporative Emission System Purge Control Valve Circuit (not the one that says malfunction).

This is where I hope there is some info here, or someone with sound advice on where to start. Thanks in advance!

 

Something is either going on with the circuit or the solenoid. Test plug if it tests good replace the solenoid.

 

Thanks for reply... does this mean I can exclude any vacuum/leak tests, and only go towards electrical connections/issues? the solenoid activated with voltage applied, so seems solenoid works, but that excludes if there is contamination causing it to not be fully closed. But, if the code is strictly circuit, then I'll work on that first.

How do you recommend to check plug? voltage? Or is that determined by car computer and it may not always get voltage, which may be hard to know when it should get signal for me to test catch it.

 

I am assuming you don't have a snap-on or any other beefy obd2 tester so I wouldn't go too far into the troubleshooting phase because it is above your means. Yes the PCM control the circuit and will have to be put on a machine to see if it's getting the correct voltage and if so what is the valve actually doing when it gets the voltage. I would put my money on the PCM not being the issue. I would take the plug out and look for any noticeable issues along the wire and plug; if it looks good replace the valve. Clean the plug up with some electrical spray if dirty.

 

Anyone know how to electrically test the connector to the purge solenoid? I have a multimeter and a test light. If it was the PCM I think I’d have bigger or more problems.
I have continuity (beep) on valve pins, and I hear solenoid activate (click) when hooked up to a 9V batt with wires with alligator clips.
I want to rule out the connector before I spend $100+ on the valve.
With pins backprobed into connector while plugged into valve and key off, the pins get 0V. With key on, pins get 16mV. With connector plugged in and while backprobed and key on, test light turns on.
So I guess connector is good, but now just need to check wires to connector??

 

Do you have a MityVac or something to test the operation of the valve? You said it clicks when you apply battery voltage. When you do that, verify the valve opens & closes by trying to suck air through it. If it passes that test, then you don't need to replace the valve.

I don't have a wiring drawing for 2004 so I can't say pin numbers or wire colors, so this'll be general. One of the wires for that valve should have battery voltage when the key is turned on. The PCM operates the valve by connecting the other wire to ground when it wants to energize the valve.

Did you verify that one of the pins has battery voltage when the ignition is turned on? It sounds like you measured across the valve, not necessarily measuring from the pin to a ground point.

What you need to measure is for each of those 2 wires to go to the correct pin at the PCM (continuity). Also for each wire to NOT be shorted to ground (when unplugged at both ends).