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Re: bad idle when defogger on

Posted: September 4th, 2009, 10:26 pm
by ganue
Folks,

For those that can follow along, please turn to page Z-44 of your factory electrical schematics (mine's a 1993). Ok. Good.

Pin 1J is a sense line for the defroster.

The Engine controller will attempt to compensate idle for the following:

1) A/C
2) Defrost
3) Blower (all positions except "low")
4) Headlights (K8 with headlights, B6 with running lights - it even turns on the DRLs in Canada!!)
5) Cooling fan
6) Power steering

OK - now go out there and try every switch!! Very entertaining....

Haven't thought to verify all the same connections to the KL36 in my ZE car, but I do know that the A/C and defrost have an effect.

There will be a wiring test on Monday.

For those turning on the defrost to LOWER your idle rpm, most likely you have a bad IAC AND you are most definitely wasting (very little) fuel.