You may have more then one issue.

The TRAC light may come on any time the CEL is on to conserve engine power.

The electrical issues such as window, shifting out of park, AC operation may be a fuse or wiring problem.

The ABS has its own trouble code readout system that can be accessed.

An IAC issue would be linked to idle problems, the engine stalling, stalling when the AC is off. When the AC is on, the IAC increases idle speed to compensate for the increased engine load.

Is the power steering pump powered by belt or electric motor?

Have you checked the PS reservoir level.

 

What model of Lexus do you have? The TRAC and ABS light will come on any time there is a CEL, which will disable the TRAC.

And toyomoho is correct that you may have more than one issue. What was your original problem that you were having?

N.E.O.

 

Sorry about the model, it's a 95 SC400. Original problems were stalling with AC off, code 27 (sub o2 sensor) trac light and CEL on. All the other stuff happened after I removed, cleaned and re-installed the IACV. I did not take the IACV apart, I just sprayed throttle plate cleaner into it.

BTW THANKS for the quick replies, I had posted this on a Lexus forum and over 10 days got only 1 reply

 

You are heading the right direction with the IACV as a start for the stalling concern. But the other items doesn't really have much to do with cleaning the IACV.

The code 27 is for the sub O2 sensor, which should have affect the operation of the vehicle, except maybe turning on the TRAC/ABS light and disabling their operation. The sub O2 is used t monitor the efficiency of the cat mainly.

Check your brake light to see if they are working, the shifter inter-lock is power by the same circuit; it could be either the brake light switch or the fuse.

The other items, you will probably have to tackle them one at a time. Start with clearing the CEL code first.

N.E.O.

 

Fixed...sorta, new problems

Fixed: power windows, trans lock, abs light off. Culprit: fuse 13 fell out, not blown, but fell out. Replaced: alternator and power steering pump, and of course, #13 fuse. PS pump was leaking onto/into the alternator .CEL, and TRAC still on. NOW the power steering reservrior is overflowing, with the cap on, and fluid is "foamy". Tried bleeding twice, works for a bit then the same overflow/foamy issue. Is this an air in the PS system issue or back to the IACV problem?

 

Did you replace the power steering idle up valve, the valve with two vacuum hose attached to it that is on the pressure line that goes into the power steering pump?

Disconnect the battery and see it the code reset.

N.E.O.

 

No, I did not replace the idle up valve. Battery was disconnected the entire time while the alt. and p/s pump were being swapped.

 

Do you see white smoke out your tail pipe?

 

Correct, there isn't much you can repair in that valve. If is drawing air into the pump and sucking fluid into the engine.

N.E.O.

 

And you may see white smoke out the tail pipe as it burns the pump fluid.

 

finally got the idle up valve yesterday, started to replace it and mixed up the vacuum lines. Does it matter where each line goes on the valve?

 

Bringing this thread back to life. Still have the trac light and CEL on. Car runs OK, stumbles once in while. NO AC. AC light is blinking. Tried to charge it, but the clutch will not engage. STILL getting code 27, sub o2 sensor, and cannot find anywhere which o2 sensor "sub o2" is:headbang:. ANY one know what the part number is for a "sub o2 sensor is"? b/c I'm replacing that before I do ANYTHING else to this car.

Here is a list of o2 sensors for a 95 SC:

http://www.rockauto.com/catalog/raframecatalog.php?carcode=1356128&parttype=5132&a=FRc1356128k501777

The word "sub" is nowhere to be found. AND it seems there are 2 upstream and 2 downstream sensors, so would "sub o2" mean 2 sensors need to be replaced?