Q: How to remove and install the IAC valve on a Cadillac DeVille and DTS?
A: On the front of the throttle body is where the Idle Control Valve (the Idle Control Valve) is located. To get it off the throttle body, just unplug the electrical connector and remove retaining screws. Disconnect cable from the negative battery terminal. Then, disconnect electrical connector from Idle Control Valve. Remove Idle Control Valve retaining screws then remove Idle Control Valve from throttle body. Thereafter, remove and discard old Idle Control Valve 0-ring then coat 0-ring with a little engine oil to protect it during installation of Idle Control Valve. Install new 0-ring on Idle Control Valve using a little clean engine oil on 0-ring to protect it from damage during installation of Idle Control Valve. Otherwise, installation is reverse of removal. This procedure applies to 2005 and earlier models only.