Should be two. One for the temp gauge (located between cylinders 3 & 5) and the other (located close to the thermostat housing) for the ECM to monitor.
one
located coolant temp sensor
Don't worry about it those screens are all faulty & blink coolant temp sensor.
Coolant temperature sensors are usually located on the radiator.
P0128- coolant thermostat ( coolant temp below regulated temp)
most coolant temp sensors are located on the intake or the thermostant housing, but i have seen some on the heads
Tps, map, coolant temp, cam, crank, knock,
There is two coolant temp sensors. One for the temp gauge that has one wire to it located on the drivers side head between two of the three spark plugs. The second second temp sensor sends information to the ECM and has two wires to it and is located next to the thermostat housing.
1 and the coolant temp sensor is located in the head under the upper rad hose
The G20 has two coolant temp sensors, one temp sensor is at the front on the engine, it has two wires and is next to the thermostat housing, this sensor feeds info the the vehicle ECU. The other sensor is one wire feed and situated on the side of the engine (drivers side) this gives info to the temp gauge on the dashboard.
There are only 2 temp sensors on the 1991 Chevy 4.3L on the intake manifold just to the left of the thermostat housing and on the passenger side head between the exhaust manifold pipes. the one on top is for the computer and the one on the side is for the temp gauge or warning light!
Where is coolant fan switch located on 1998 chevy Malibu with 3 .1