All Subaru dealerships in New England (ME, NH, VT, MA, RI, CT) buy all of their new Subarus from an independent distributor named Subaru of New England (SNE), not from Subaru of America. SNE recently sent a memo to every New England Subaru dealership (see attachment). This memo provided advice about the following WRX Diagnostic Trouble Codes (DTCs):
P0340 - Camshaft position sensor circuit malfunction.
P0457 - Evaporative emission control system leak detected (fuel filler cap loose/off) [Note: This DTC isn't defined in the WRX service manual so this definition is per SAE J1202].
P1443 - Evaporative emission control system vent control function problem.

It occurs to me that if some WRX owner in New England actually wanted to trip one of these codes so that he could get his ECU reprogrammed, he could easily cause a P0457 whenever he wanted. I don't, of course, recommend that anyone do this.

Attachment removed per the request of the author of the Memo that was attached... do not reattach. Jamie/subiegal.com

The now-removed attachment said that SNE Technical Training now has the equipment required to reprogram ECUs on the following vehicles for the conditions described below:

02MY Impreza WRX:
DTCs P0340, P0457, or P1443

If the service technician finds one of these conditions, he's supposed to diagnose the problem thoroughly using the factory service manual recommendations before contacting SNE Technical Training.

Question is....

Does the reprogramming do anything else? There is rumors that some cars like the Celica got a few extras after some ECU re-work.

My wife's WRX wagon had the evap error and got a reprogrammed ECU

I cannot detect any noticable change in it compared to the old ECU code

So why force the error?

Good info Jon!

Originally posted by tt_ttf
Question is....

Does the reprogramming do anything else? There is rumors that some cars like the Celica got a few extras after some ECU re-work.

My wife's WRX wagon had the evap error and got a reprogrammed ECU

I cannot detect any noticable change in it compared to the old ECU code

So why force the error? Hey, that's two questions. I can't recall a single person who has reported on these forums that the reprogramming made his car worse, or better (except for no more MIL illuminated). Could reprogrammed ECM be making better power or mileage? I guess it's possible but, apparently, nearly undetectable.

Here's three reasons why someone might want to "force" a reprogramming:
1) Suppose you're driving down to Miami next month for a few weeks with the grandparents/parents/in-laws. You might want to get the reprogramming done just as part of your preparations to reduce the number of things that could go wrong on the trip. Who wants to track down the nearest Subaru dealer to Valdosta, GA because your MIL popped on as you were making a turn into McDonalds?
2) You've got your WRX all broken in and now you're about to swap on some serious horsepower upgrades. Once you've done the mods, you become REAL reluctant to let your service department "inspect" them and they can be a PITA to remove. So you get the reprogramming done BEFORE the mods go on.
3) You've got a new WRX and you simply want an "up to spec" ECM.

And, Glenn Wallace. The presence of your epic "WRX CEL Log" thread is the reason I posted this info in this particular forum . I suppose this thread will drift away from the Log fairly quickly, though. Oh well. C'est la vie.

Great post Jon, as always:)

Very interesting information.

I'm not in New England technically, but I've had my fair share of CELs.

Mulder helped me pull the codes last night with an AutoXray scanner. We got 2 types: 0340 and 1443.

Unfortunately, the AutoXRay doesn't offer enough information to accurately determine how many of each type you've had and when each happened. For all I know, perhaps the ECU doesn't even store that info, so I've got a couple of questions for anyone with even a little more knowledge than I:

1. Based on the description above, a loose gas cap would cause an 0457, not a 1443. I've seen a lot of posts on these boards from folks chalking up 1443s to loose gas caps (I've been ignoring them too), but this may be a more serious problem. What would cause so many 1443s?

2. Would an extreme overrev cause an 0340? By extreme I mean in the 8k - 9k range?

3. Has anyone had their ECUs reprogrammed by a New England dealer, or elsewhere? Where? What's the name of the dealership that did the service?

For now, I've just cleared all the codes from the ECU and am waiting for the problem to reoccur. The reason I cleared them is because I don't want a Subaru dealer to pull the DTCs from the ECU and see in the snapshot info engine revs way in excess of redline. Which leads me to my last question:

4. Can the Subaru dealer read DTCs that have been 'cleared'? Does the ECU keep a separate log of DTCs?

Thanks.

J

Originally posted by BluJay
1. Based on the description above, a loose gas cap would cause an 0457, not a 1443. I've seen a lot of posts on these boards from folks chalking up 1443s to loose gas caps (I've been ignoring them too), but this may be a more serious problem. What would cause so many 1443s?1. AFAIK, the 1443 is triggered by excessive moisture in the vent control solenoid valve. The tolerances were set too tight, so the ecu sees moisture when there is none. Reflashing takes care of this.

I got the PO457 trouble code over the weekend (11/2/01 - documented in the CE log thread), took it to a dealer, had it cleared. This morning on the way into work (next tank of gas after the weekend), the CEL came on again. I have a sneaking suspicion it's probably the same problem. I don't want to take it in to the dealer because it's too far away, but am wondering if there's a 'permanent fix' for the PO457. Is it possible that the plastic gas cap has suffered some wear that prevents it from sealing properly? Also, I've seen that some people have pulled their own codes - how do you do that? I don't like the prospects of getting a CEL each and every time I fill up for gas. :(

bliu, if you can't detect any cracks in your fuel filler cap, then it's extremely unlikely that your gas cap is defective. The usual (normal) causes for this trouble code are:
1) refueling while the engine is running or the ignition key is in the ON position
2) failing to replace the cap after refueling completed
3) cross-threading the cap
4) failing to tighten the cap properly (I like to hear it click 3 times).

The unusual (abnormal) cause for this touble code is that the ECM wasn't programmed correctly at the factory, the subject of this thread.

As far as extracting the code without driving to the dealership, you'll need to find someone with a general scan tool which works with Asian or European cars not manufactured by Ford or GM. You might be able to get an auto parts store to read it for free. Or you could scam them: "Gee, I don't know if I want to buy that scan tool unless I know for sure it works in my car. (minutes later) Wow, it seems to work. What is that trouble code? Damn, is that serious? Thanks. Gotta get the wife's permission first, though. Seeya." Or you could wait until Thanksgiving. That's when the wife and I are driving the WRX down to our condo in Cocoa Beach and I'll have a scan tool with me. :)

Jon-
I know that my CEL doesn't come from 1, 2 or 3. I think I may be having trouble with number 4. I always have closed the cap till it clicks a few times. I was just looking at it, though, and I noticed that at the bottom of the circle, both the filler opening and the rubber seal on the cap were a bit damp with gasoline. I would have to assume that a rubber seal should remain dry, since it's supposed to providing an air-tight seal. I will try to contact a dealer about getting a new cap. (I would also like any and all to chime in on whether their gas caps exhibit any dampness, please!)

I think I'll take you up on your offer to scan mine for me. :) Thanks so much for being willing to help out! I suppose I'll have to temper my paranoia about having a lit CEL, though. :o

I've had my WRX for 6 months now, 10,500 miles, no problems at all, never pulled a cel ... haven't even installed my up-pipe yet.... suddenly tonight, i got one.... I was on the freeway doing about 70 mph.... I was like oh crap.....!! I wasn't over boosting or anything.... slowed down to about 60, car felt fine, got home, pulled my code (1443) with my OBDII Scanner..... came in and found this thread.... well, I had just done 2 things tonight before getting on the freeway, one, I leave the accessories on (key in ignition) while pumping gas (92 octane Amoco) and, as it turns out, my gas cap was not on as tight as usual..... (I found this out when I went back out there, after reading this)

So, for now, I just reset the code, started it up again, everything seemed fine. (no cel) I will be watching this over the next few days for anything else, I'll probably bring my laptop with me to monitor it.

Be sure you post it in the WRX Check Engine Light Log (http://www.i-club.com/forums/showthread.php?s=&threadid=36779&highlight=wrx+Check+log)
Edit: You already have...:p

1) refueling while the engine is running or the ignition key is in the ON position

Now I know how I am throwing this CEL. I left the engine running while fueling (bad practice I know). I tried the ON position while fueling tonight and threw it again after driving 2-3 away from the station.

i have never had that problem with it until tonight, but i got pretty well modified engine... fuel rails, and stuff.. and i think i have a vacuum leak after installing them..

Time to go figure.