Falsely overheated

31N007

31N007
:
Mazda Protege5
Is a factory crimp. There are many like that on other circuits throughout the loom.

EDIT:

A lot of what I said was already said/asked.

I would suggest plugging everything in as it was, and hooking that orange wire up as it was to the ECU. Start from scratch.

Withkey on/engine off, monitor the coolant temp sensor as you unplug the sensors on that circuit:
Throttle position sensor
Intake air temp sensor
Both O2 sensors
EGR boost sensor

the fuel tank pressure sensor is hopefully not at play, but that'll be under the fuel pump access hatch beneath the back seat.

If that doesn't do it:

Start unplugging the rest of the sensors too. At some point, whatever is causing issues will not be in the circuit, and the ECU will either stop saying "HOTTTTTTTTTTTTTT" or there will be no change...
 
Last edited:
  • Like
Reactions: pcb

pcb

The Diagram Dude
:
2002 MP5
I did a couple of tests on my car and unplugged the temperature sensor but the temperature gauge read low.

I wasn't expecting that. I thought it would read max.

I checked the voltage and I was getting ~4.5 volts.


Then I pulled my engine fuse from the fuse box in the driver's wheel well and my temperature gauge went to Max.


Check your engine fuse specifically.
If it's blown, it shuts down the car.


 

31N007

31N007
:
Mazda Protege5
Yeha,so I wonder if maybe I was the idiot for thinking it'll read high temp if the ECT gauge is unplugged. I think I owe OP an apology if that's the case.
 

pcb

The Diagram Dude
:
2002 MP5
I tried to remove the orange wire from my connector.

It was more complicated than I expected.









Then I realized that you "unclip" the wire from the other side of the connector, not the wire side.

You remove the red piece to gain access to the pins.






The wires/pins "unhooked" quite easily.





You reach in with a needle and push open the tab and the wire comes out.






To the OP, ... Your orange wire and its clip should be fine.
You may have broken the little plastic tab that holds it in place but it should be fine with the rubber "seal" helping to hold it in place.

Push it into its hole and check at the red cover to see if it's fully seated like the rest of the pins.


Get yourself a multimeter and check the voltage at your temperature sensor.
A cheap one is all you need and is easier to operate than a complicated expensive one.
It should only cost about $10.

My DD was reading 4.5 volts at my temperature sensor.
If you are getting more than 5 volts at the temperature sensor then there is a pretty good chance that your ECU is fried.
 
Last edited:
Top