Magic scanner??

[Mark Babunovic]

Hi everyone –

2002 Honda Accord 4 cyl with 186k miles. Twice in the last three months the CEL has come on, setting a P1519 (Idle Air Control Valve circuit fault) simultaneous with a rough or hunting idle. I haven’t had idle problems before so I’m not sure which it is: the idle oscillates just over/under 1,000 rpm at cold start, and while driving when the rpm drops to that level.

Here’s the odd part: both times, when I then erased the code with my no-frills Actron Pocket Scanner, the idle problem itself disappeared. It’s been 3 days since the second episode, and the engine starts and idles as smooth as silk. I’m not one to look a gift horse in the mouth, but does this point to something I should check, besides the connector which I’ll take a look at this weekend?

Or should I just hold on tight to this scanner and look forward to fixing problems just by clearing codes 🙂

Topic

[Rob]

I would try cleaning it first and see if you have any luck with it ater cleaning it….. might have to replace it and see if that fixxes it also check for any vacuum leaks

[Mark Babunovic]

Thanks Rob. I hesitate to take anything out yet, especially because of the weird “fix” of what is an intermittent problem. Obviously something’s causing the idle to misbehave before I clear the code, but then again the IACV isn’t so dirty, or otherwise faulty, that it doesn’t go back to normal. I’m wondering if the combination of the “circuit malfunction” code, and the fact that clearing the code also clears the condition, points to something electrical. Again, I’ll have a look at the connector/wiring this weekend.

[Shaun Flichel]

Just clearing the code erases the pcm’s memory. It’s not a fix. If it’s intermittent it may take awhile to reset that code.

[Mark Babunovic]

Thanks Shaun — I understand that — it’s just an odd coincidence that the idle problem disappeared when I erased the code. The two times this has happened the CEL & code showed up at the same time as the erratic idle. I’ll check the connector, keep an eye on it, and come back to everyone with a wrap-up. Hopefully.

[Mark Babunovic]

To close this out, I replaced the IACV yesterday, which fixed the hunting idle. It had gone from intermittent to constant, and I was concerned the fluctuations were putting a strain on the transmission at lower speeds.

Not much room back there between the throttle body and firewall — I ended up disconnecting the other ends of the coolant hoses and vacuum line, then pulling them up and out with the part.

Thanks for the tips.

[Author]

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