need help with P0443 Engine code

[volsmd99]

So I just got this code the other day. Here's the back story: Got gas at Walmart last wednesday (never will do that again), washed and waxed my car over the weekend, changed the transmission fluid, and then sprayed undercoating in the wheel wells as it had worn off. On monday, driving home from work and got this code. It was reset at Autozone that night. Tuesday, everything was fine. Then wednesday morning while driving to work, got the code again. It was reset that night and now today Thursday it's back.

I know the code relates to the evaporative emissions circuit. Is there anyway that any of the above events triggered this thing. Either way, I was going through my Chilton's guide and was thinking of testing the system to make sure everything is alright. Apparently I need a purge flow indicator (MB991700) and a hand vacuum pump. Any idea of where to get these tools other than at the dealer. And also, if anyone has any trouble shooting tips.

thanks in advance

[gthompson97]

What year and model?

[volsmd99]

1995 Eclipse GSX

[gthompson97]

Pulled straight from Mitchell On-Demand Enjoy.


CODE P0443: EVAP CONTROL SYSTEM PURGE CONTROL VALVE CKT FAULT
NOTE: For component terminal identification, see TERMINAL IDENTIFICATION in this article. For appropriate WIRING DIAGRAMS, see WIRING DIAGRAMS section.


1. Label and disconnect both vacuum hoses from purge solenoid valve. Disconnect electrical connector. Connect hand vacuum pump to solenoid valve nipple where Red-striped hose was connected. Apply vacuum to solenoid valve. Vacuum should hold.

2. Apply battery voltage to terminals of solenoid valve. Vacuum should bleed down when voltage is applied to terminals. Using an ohmmeter, check resistance across solenoid valve terminals. If resistance is 36-44 ohms at 68°F (20°C), go to next step. If resistance is not 36-44 ohms at 68°F (20°C), replace valve.

3. Disconnect purge solenoid connector. Turn ignition on. Measure voltage between solenoid connector terminal No. 2 (Red wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, check wiring harness between MFI relay and purge solenoid connector.

4. Disconnect PCM connector. Turn ignition on. Measure voltage between PCM connector terminal No. 9 (Light Green/Black wire) and ground. If battery voltage exists, check PCM connector. If PCM connector is okay, replace PCM. If battery voltage does not exist, check purge solenoid connector and wiring harness between PCM and purge solenoid connector.

[volsmd99]

Thanks for the info but where do I get a hand vacuum pump and in Chilton, they mention the need for purge indicator tool.

[gthompson97]

I would use this over the Chilton manual, therefore eliminating the need for a purge indicator thingymabob. You should be able to find a vacuum pump at any autoparts store or if you have a Harbor Freight around your area I know they sell them there for like $15. It's just a "hand pump gun" with a vacuum gauge on it, very simple tool. What I would do first though is just check all the connections to make sure the system is connected properly and it's not just a loose/shitty connection causing the CEL.

[volsmd99]

thanks for your help. I have one more question, when it says "apply battery voltage," how is that actually done. Do I need special cables?

[gthompson97]

It's usually done with a voltage producing machine, but you should be able to do it with your battery, IIRC.

[volsmd99]

Do I need a particular guage wire to connect the battery directly to the solenoid valve? I just want to do this right.

[volsmd99]

So I think I've isolated the problem. I wasn't sure what gauge wire to use to apply the battery voltage so I just tested the resistance of the purge solenoid valve terminals. I'm getting around 62 or so which is clearly out of the reference range. I did not test the vacuum using a vacuum pump. Unless I'm wrong, having the out of range resistance probably negates the need to test the vacuum.

Any thoughts ...