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three
03-22-2008, 05:19 PM
does anyone know the ohm specs for the blue engine coolant temp sensor?
(I searched)

that would be helpful.

I always get a pending code p0118 ECT circuit high...

should prob just replace the thing but im a college student so im cheap.

I suspect its the connector and not the sensor itself so if I can check the resistance ill know for sure if the sensor is going bad or not.

Thanks

chris164935
03-22-2008, 09:02 PM
Uhhh. Coolant Temperature Sensor is a variable resistor. I'm going to assume you have an engine coolant sensor with an oval connector. Use a multimeter to check the resistance between terminal C and D (these are the terminals on the side of the sensor that isn't a half square) and check back with your findings.

As for checking the connector, you'll have to check for a short or ground by testing terminal 3 on the connector and terminal 108 on the harness connector that connects to the ECM. You will also need to check terminal 4 (signal) on the connector and terminal 93 on the harness connector that connects to the ECM.

three
11-09-2008, 12:12 PM
bump

well i still have this thing intermittently going on

The ohm specs for my sensor are
aprox 3k ohms for one side and around 6k ohms on the other. this is at around 32 degrees with the engine cold.
the wiring harness seems to have a solid 5 volts across both sides of terminals when i checked KOEO.

So honestly,
some specs for a blue top ECT for a v6 1998

maybe you just bought one, or have one sitting around, run an ohm meter across it, and also record the temperature (prob room temp) or around 70* F at which the readings were taken.

and also, i do know that an ECT is a variable resistor, that is why there should be a table somewhere of resistances values at various temperatures. most car companies provides this information for their vehicles somewhere.

hence the default temp reading for an open (0 volts returning to computer) is -40* F and thats
why i think its the connector since its intermittent.
with the main symptom being hard starting on a slightly warm engine (computer thinks engine is cold and dumps too much fuel).

any help would be appreciated.
more details for checking the harness would be also appreciated.

djwimbo
11-09-2008, 12:59 PM
hence the default temp reading for an open (0 volts returning to computer) is -40* F and thats
why i think its the connector since its intermittent.
with the main symptom being hard starting on a slightly warm engine (computer thinks engine is cold and dumps too much fuel).

any help would be appreciated.
more details for checking the harness would be also appreciated.

if you're having a hard time starting the engine when the engine is up to temp, try pushing your foot down on the "gas" pedal. That will signal the ECM to crank in "clear flood mode" meaning it turns off the injectors temporarily.
Don't pump the pedal, just hold it to the floor while cranking. That's how the ECM knows to go into the clear flood mode.

I'll see if I can't pull up the ohm specs tomorrow at work, but honestly I'd just put a CTS in it.

Chris, his is an early car. Meaning he has the square connector and the blue sensor. We don't get the option of the "D" connector and green sensor.

three
11-09-2008, 10:51 PM
yep, that is exactly what I have had to do to start it when it acts up. Clear flood mode.

edit: this is actually why I think it might not be the sensor itself, since its intermittent, only seems to affect during a semi-warmed engine, and is usually worst in the rain.