What are these Sensors?

[divemaster5734]

These sensors are on each side of the engine, by #1, and #2 cylinders.
I thought the one on the even side was the water temp.
I know the oil sensor is in back just off center of the block.
What the one by #1 ?

 

[Nero]

First one is the fast idle/timing advance for cold start, second one is the gauge coolant temp sensor.

 

[divemaster5734]

First one is the fast idle/timing advance for cold start, second one is the gauge coolant temp sensor.

Does that signal go to the PCU that then activates the solenoid at the IP?

 

[IDIBRONCO]

Does that signal go to the PCU that then activates the solenoid at the IP?

I'm not sure what a PCU is. That sensor is just a temperature activated switch. When the engine's cold, it allows current to flow though it, which then powers the fast idle and timing advance. When the coolant temperature gets to around 120*, the switch opens, and keeps the current from going through it which deactivates the two.

 

[Nero]

I think he's referring to that little black box that hangs off the harness. Yes its necessary but I don't remember what its purpose is.