What were and how? Error Code 42 Idle Switch
 

bloody subaru's lol

just changed both the ICV and TPS as the car wasnt able to idle and error codes said they were faulty.

But since, another one has come up, code number 42: Idle Switch???

What is it?
Where is it positioned?
And whats the general fix for it, or is it just replace?

All i know is it feels as though the Throttle body gets stuck closed, so you dont have as much control with the throttle pedal, as you need to push that bit more to open it?

Help Appreciated Guys

Thanks

Terry

anyone?

thanks

anyone? is it possibly just the tps needing adjusting?

Hi Terry,
I have a no.42 fault code which i can't get rid off. Are you still having problems, if not I can you tell me how you fixed it? I have already replaced my TPS (the idle switch is part of the TPS) but it hasn't fixed the problem.

any help on this would be greatly appreciated.

Cheers.

If you are running a 1993-1996 UK spec car on a WRX ECU or WRX/STi Map code (i.e the Prodrive base code or ScoobyECU style chip that msy of inherited this running/diagnostics code), then you will log a red herring CEL for the idle switch.

It doesn't cause the CEL to illuminate normally. Just flashes the code when you do a diagnostics check.
Don't worry about it as it has no effect. The Prodrive Upgrade for UK car's does has always done this for these MY.

Thanks for the reply Scott,

i've had an ESL daughterboard fitted for well over a year now with no CELs at all until now. This problem only occured on friday - whilst sitting at traffic lights the CEL came on and the car's revs increased to 1500rpm. as soon as i touched the throttle the CEL goes out but comes back on again when you take your foot back of the throttle. i have already changed the throttle body complete with TPS attached over with a spare i had but the fault is still there. i have measured the voltages at the ECU and i am getting 0v with the throttle closed and 4.8v with the trottle fully open, so i think everthing is how it should be.
any ideas where to go from here?

Cheers, jonjoe.

If the car is a WRX, then what you have measured is the throttle potentiometer. Not the throttle switch.
If you have changed the throttle housing etc.. I would check the wiring at the ECU or even drop another ECU in to try (any WRX ECU on ebay will suffice).
If another ECU fixes it then try with the j1 link re-attached to disable the ESL board in order to try an eliminate/diagnose.

Thanks again Scott,
the car is a 1995 STI with a 4 wire connection to the TPS, I take it that not all models have an idle switch within the TPS then?
I've just removed the ESL board and resoldered the j1 link but no change, at least I know it's not the ESL board. i've already checked the loom out with a multimeter and that seems ok so I'll check out Ebay for a replacement ECU.
meanwhile, if you have any other ideas let me know.

your help is appreciated,
jonjoe.