This second bus I'm working on, the high idle is not working. I swapped controlers just to see, (even though the LED was working) No change. Took apart, ohmed out the wire to the ECM. Grounded it directly, no high idle. Check voltage, and had system voltage to ground (14v) No high idle. No SES light, or codes present. Seems a little fishy.

Thoughts?

possibly a problem with either the brake switch or neutral safety switch making the ECM kick out of high idle.



Tim

edited for clarity

Thanks Cowracer. I had thought about the brake switch, but seems to me on an OBD-II system, it kicks out a code if the brake switch is stuck. . . maybe I'm wrong. Everything starts up okay, and seems to be okay without an issues that would show up with a NSS going up. Unless there is a second switch in there that the ECM doesn't see.

IIRC there is like 3 or 4 seperate circuits in the brake switch. One is for the lights (natch) and the others are for various functions (kicking out the cruise control) and so on. It is "possible" that the one that stops the high idle might be flaky. Does the cruise work?

Also check the Neutral saftey switch. It might have the same multiple circuit setup.

Tim

Cruise works. Still confused. I guess I need a shop manual here for diagrams.

Thanks!