Can someone tell me where the Engine Coolant Temperature Sensor (ECTS) is located on a DOHC 1.9 liter motor? If you have an electrical diagram too that would be helpful. Thank you.

ECTS is mounted in the cylinder head and located on the driver's side of the head - -find the EGR valve and look down.... It has two wires coming off a SQUEEZE connector (do not try to pry it off). It should be the only 2-wire device you find in that area.

If you are replacing:
1) Use brass-tipped sensor replacement
2) REPLACE THE CONNECTOR too (Saturn-only part). Corrosion here is a killer and can hose the temp reading from a brand new sensor.....
3) Replace the connector (just do it--the $20 will be worth it)

Derf

Thank you derf. I have the sensor, the new connector, and thanks to you, the location. Regards, SC2 owner.

I replaced the sensor and the connector assembly (very good advice regarding replacing the sensor connector also, spend the extra $23). The sensor had a split in tip and coolant had leaked into the connector area. With the new sensor and connector the engine temperature has never been so well controlled. It fluctuates slightly around the half-way mark now. This was money and time well spent to fix a nagging issue. Thanks for your help!

very common for the earlier S Cars.....

Glad to help!

Derf