starter switch?

[MPtyza]

I had my uncle pull the engine codes the other day on my Legacy, because I'm getting it ready for inspection, so I can finally drive it. The codes that were present were 12 and 22.

I know 22 is the knock sensor code, so I ordered a new one from 1stsubaruparts.com for $46 or so.

12 though, I'm not sure about. I know it's for the "starter switch", but what causes this code to pop up? I believe the car has a new starter in it, so I'm kinda confused on this one.

I really need to get all this cleared up since it won't pass inspection with the CEL on like it is.

I have searched on this, and haven't come up with much, so any help would be appreciated.

Thanks

[vrg3]

It could just be a spurious code that doesn't mean anything... After you replace the knock sensor you might be able to clear the codes and not see 12 come back.

In any case, the starter switch is just a wire from the ignition switch's "start" position to the ECU, telling the ECU when the engine is cranking so it knows to do things like fix timing at 10 degrees BTDC, use nice large pulse widths, etc. If the engine cranks but you get a starter switch failure, the problem's pretty much got to be in the wiring or in the ECU.

I say most likely there's no actual problem, assuming the car does start reliably now.

[MPtyza]

Yeah, we cleared the codes and the 12 did not come back, but a 23 did. I'm guessing that he misread the 22 as a 23.

Now, 23 is the air flow sensor. Would that cause a stumble in the engine at around 3500RPM? We had taken the car out for a quick drive after doing the rear brakes, and every time it got up to about 3500, it would stop acclerating, and the RPM's would drop, and come back up. Is the bad air flow sensor causing this, or is it something else.

I had already ordered the knock sensor, but since the one in the car is the old style, gray connector, I guess it's not a bad idea to replace it anyway.

Thanks.

[vrg3]

Yes, it's plausible that the stumbling could be a problem with the MAF sensor. You might want to try cleaning your sensor out.

[Kelly]

Yeesh, ya the MAF is a spendy little peice. I always look for em at the wreckers.

[MPtyza]

Heh, yeah, I'm finding that out real quick . I did know it was expensive, but never knew how much they were.

edit- Is the MAF also to blame for the fact that the car would not start at all for about 10 minutes? It started fine before and after this 10 minute span.

Thanks again.