MoogLe

Hi guys.

I have a 2003 Honda Accord Euro R (which is very similar to a US Acura TSX) and a while back I got this error code after I replaced my intake.

I know this error code has to do with an electrical problem in the EVAP Canister Purge Valve circuit and I'm thinking it may be due to me accidentally mixing up the connectors of the Evap solenoid and the TPS / IAC / MAP sensor (cant remember which one it was but two of those sensors have identical connectors).

After doing that, I got this error code ever since.

I've done allot of reading up on this trouble code and how to trouble shoot it but I'm not 100% sure how to proceed.

I've measured the voltage at the connector and it's measuring 0V, So I thought maybe there's a fuse that blew? But I cant seem to find a fuse labelled for the EVAP solenoid. Anyone know which fuse controlls that? Either way I went over all the fuses and they all looked fine.... But I'd still like to know if there's a specific fuse for this.

If it's not a fuse, I looked up the pinout for the ECU and I'm going to check if there's any voltage there. If there is.... I'm guessing maybe the wire may be damaged? Can I just run a new wire to the sensor? Here I'm coming back to the fuse question....

If there is NO voltage.... What then? Bad ECU?

Hope somebody can help me out with this.... I really hate electrical troubleshooting!

DuckDodgers

OK, on a '04 TSX, a P0443 is "Evaporative Emission (EVAP) Canister Purge Valve Circuit Malfunction".

Troubleshoot: Check for vacuum pressure at EVAP Canister Purge Hose.

If you have vacuum, check for continuity between EVAP 2P connector terminal 2 (YEL/BLU) and body ground. No continuity, possible short.

No vacuum, check terminal 1 (BLK/YEL) and body ground for battery voltage with ignition switch on. No voltage, possible short or fuse #18 under-dash blown.

After this you get into ECM/PCM issues. The check is to jump the 2P terminal 2 to ground and check for continuity between ECM/PCM B21 (24P connector, YEL/BLU) and body ground.

One other thought is at room temperature you should get 33 ohms resistance between terminals 1 and 2 of the EVAP 2P connector.

MoogLe

good info,

I already checked a few of those.

I'm going to number all your suggestions to refer to them easier.

1. I don't have a vacuum gauge. I used my thumb on the hose and I think I could feel a VERY light vacuum. Im gonna look for a vacuum gauge later this week

2. I'm not getting any continuity doing this test

3. No voltage whatsoever. Fuse 18 is fine, I even switched it out just in case but still no voltage.

4. No continuity

5. Measured approx 33 ohms like you said. I also tested the solenoid by jumping it with a battery and it was clicking.


So... from the above tests, would I be correct in assuming that the wires for the connectors are probably damaged somewhere?

Another question. Is the B21 pin on the ECM ground or positive?

DuckDodgers

OK, if no continuity on #2, replace EVAP canister purge valve is called for. #3 seesm to confirm that.

I'd try replacing the EVAP canister purge valve if you are sure you have vacuum and are getting no continuity.

On the question, since you are checking for continuity to ground, I would assume positive.

MoogLe

hmmm wait i think i did some of the tests wrong

was i supposed to measure the continuity for #2 on the valve's connector or the harness's connector? does the harness need to be plugged into the valve?

same question for #3

DuckDodgers

Test would be via unplugging the connector and checking the connector, not the valve body portion. You are checking the wiring and voltage TO the valve.

MoogLe

that's what i did

So if that's what i tested, then how do you figure that the sensor is bad if it's not getting any voltage or continuity from the wires?

DuckDodgers

OK, now we are both confused. I think I missed a step, and when you asked something about it, I responded incorrectly because I followed what I was thinking instead of rereading the process...let's try again.

I've re-read the process and it calls for jumping the SCS line with the HDS between tests...we're outta luck there.

If there is vacuum:

First test before jumping SCS is EVAP Terminal 2 (YEL/BLU) and body ground for continuity...yea, the EVAP side, NOT the wire side, that's where I messed up. None and you replace valve. Continuity, then if you can jump the SCS, unplug the ECM/PCM Connector B (24P) and recheck. Continuity, then short from EVAP to ECM/PCM is fault. None, ECM/PCM is at fault.

No vacuum:

Disconnect and test EVAP Terminal 1 (BLK/YEL) to body ground. No voltage, short EVAP to No. 18 underdash. Voltage, then jump SCS, disconnect ECM/PCM, jump EVAP Terminal 2 to body ground, then check ECM/PCM Connector B #21 to body ground. No continuity, short between ECM/PCM and EVAP...continuity, then check ohms between 1 and 2 on EVAP. 33 ohns, ECM/PCM fault...otherwise EVAP valve replace.


Big problem is I have no idea what SCS is or how to jump it without an HDS unit.

MoogLe

:'(

I was just about to ask what SCS is.....

Argh.... I guess I'll just have to gamble $100 and buy a new valve to see if that helps

DuckDodgers

I'd test the continuity from terminal 1 or 2 (depends on vacuum presence) and that might answer the valve is bad...

Honestly, if you've reset all the conections, unless something weird (or rodentine) is going on, it's very rare to have a short without something that bends the wire (think truck lid wiring loom).

MoogLe

i did test that and was getting around 30 ohms. I also jumped the valve to the battery and it clicked as if it was working.... maybe the sensor that senses the vacuum could be bad?

Like i said, I was messing around with the intake before I got this CEL and I did get 2 connectors mixed up in the process.

DuckDodgers

Got me, I;m just running the troubleshooting tree...and it doesn't show an independent sensor for that. Just because power makes the valve work, doesn't infer that it'll work normally because something else may be wrong. It's also possible the mix-up caused the light and a reset of the light will show it doesn't reoccur.

MoogLe

i meant that the valve may have an internal vaccuum sensor that is not working.

and i already tried resetting the CEL various times which did not work

But, thanks so much for all your help so far, you've been very helpfull but unfortunately I lack the tools to correctly troubleshoot this.

I'm just going to have to blindly buy the valve and hope that it solves the problem

DuckDodgers

Honestly, that's likely the cheapest plan...if the valve is bad...if not, shrug.