03 saturn l300 has high idle - 2003 Saturn Ls 4dr Sedan

You need to get it checked with a scanner to see what the issue is.
Most auto parts stores will check it for free and give you the code.

About 2 hours.

6 hours or about $600.00 USD plus parts.

Saturn L-Series - Automatic Transmission Fluid Change ...

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https://www.youtube.com/watch?v=X6Ga3MESkqo
Sep 13, 2013 - Uploaded by DJDevon3
Procedure for changing the ATF in Saturn L-Series vehicles that ... I HAVE A 2004 L300 AND I WAS MAD THAT THEY DID NOT PUT A DIP ...

Saturn L-Series Questions - how do i check transmission ...

Best solution www.reliable-store.com has books on every vehicle and also how to service/repair it.
service/repair/owner's/maintenance manual with
parts info, fuse box, gear box, PCV, torque specs,coiling, wiring diagrams, electrical diagrams, fuse diagrams, error codes, etc everything
Worth it

don't know if there is one . trans. is variable belt.speed.
and if there is one it's control by the double pole brake light switch.

Check cleanliness and operation of the idle control valve.

Yes, the trouble is in one of the contacts inside that multi-function switch.

u are going to have to replace the turn signal switch to correct this.

You are not the only one. Ive met a good many of Saturn owners (most were 2001 L300 drivers) but they were plagued with the problem you have and practically identical codes. The following remedies have been known to work:

1. Replacement Battery Cable
2.Replacement ECU Wiring Harness
3. Replacement of ECU