1st code was P505 only. Replaced IAC valve. Still problem. New code P1508. What do I do now?

Question

2001 Honda Prelude 4 Cyl, 1st code was P505 only. Replaced IAC valve. Still problem. New code P1508. What do I do now?

Answer 1

Hi there

This code means there is an issue with the wiring or the new IAC itself. I would put the old one back in and clear the codes as a test. It's possible the wiring harness isn't tight at the connector.

Also, sometimes a vacuum leak can set of the IAC code. The computer can't control the idle so it will blame the IAC even if it's not the problem.