Idle Control System Malfunction

[rocky2889]

Lately, my 98 4Runner has problem starting in the morning. I replace the TPS sensor. The problem is the same no improvment. The usual idle around 600 rpm a low.

This afternoon I drive home after work suddenly the check come on and the rpm around 1100 at stop light. I think is very high for idle. I went to Kragen and check out with the reader is P505 which "Idle Control System Malfunction"

What should I do to repair the malfunction?

Thanks

Rocky