RE: 2004 Prius, 98K miles I recently replaced the coolant control valve (received code P1121) and added coolant. Trouble codes were cleared. I am now getting the red triangle intermittently. When I drive the car, after a few minutes, the red triangle comes on. I can shut off the car, and turn it back on, and the red triangle comes back after a few minutes. The car seems to drive normally. I have the mini VCI cable and the Toyota TIS software. There are no trouble codes present, but I am getting the red triangle. Does anybody know what is going on, and how to fix it? Thanks in advance. Steve
Well I would suggest you check the usual oil and coolant levels. Make sure all the air is out of the coolant loop.
Use the real time monitor function in techstream to look at your engine temperature. It should be close to 90C or less.