torque converter solenoid

i have a 97 with a 4.0 and a auto 340 transmission. the torque converter control solenoid is bad i found out and is settign off my check engine light. the mechanic who used the scan tool said there was 3 or 4 solenoids above the pan. if any one replaced this would they give me a little help by telling me which solenoid is the torque converter control one. and how much the part costs just to get me in a ball park range of the cost of all this.

thanks