When it gets warmed up it will not idle. It surges from about 1200 RPMs to about 2500 rpms, I cannot see anything wrong under the air cleaner except I noticed the kick down cable from the trans is not hooked up or is broken I don't know what it is supposed to look like. I also cannot find the switch to activated the trouble codes. Help Please.

Try replacing the temperature switch PN 008-542-32-17. If it is faulty it will mess with the idle air control valve and cause weird idle.

Check for vacuum leaks

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Could also be the Potentiometer sensor on the side of the air flap assembly.

Mine had issues all the time, that's why its a diesel now. The OM601 will idle all day long without a care.

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