Author Topic: Coolant Temps sensor  (Read 2301 times)

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Offline daveismissing

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Coolant Temps sensor
« on: June 17 2019, 12:41:18 PM »
How often have you guys found these to die?First one for me.
I have/had a no start condition and the MAL code was 15. Sensor is definitely bad, just hard for me to grok how it can cause a no-start?
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Offline nocooler

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Re: Coolant Temps sensor
« Reply #1 on: June 17 2019, 01:32:23 PM »
Computer uses coolant temp as a variable in fueling calculations.
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Offline reality

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Re: Coolant Temps sensor
« Reply #2 on: June 17 2019, 02:48:50 PM »
We used to run around all the time with that unplugged. The computer would think it was -40 ambient all the time but we never got a no start so IDK.

Offline daveismissing

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Re: Coolant Temps sensor
« Reply #3 on: June 18 2019, 10:07:34 AM »
Thanks Ron, what you say makes sense to me - I can't reconcile that to what happened.

Perhaps putting luggage in the trunk will cause a no-start condition.  :icon_eyes:
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Offline nocooler

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Re: Coolant Temps sensor
« Reply #4 on: June 18 2019, 10:14:15 AM »
Think of it the other way. The sensor probably failed at 255F or whatever it's max is. Cold coolant = more fuel, Hot coolant less fuel. Add in no cold start assistance - as it's based off coolant temp and it probably wasn't enough fuel to light off a cold engine.
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Offline Steve Wood

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Re: Coolant Temps sensor
« Reply #5 on: June 18 2019, 10:14:19 AM »
Dave, one of my cars will not run if the sol fuse blows.  It has no check engine light, no nothing.


The other car runs perfectly if it blows.


The sol fuse should have nothing to do with a no start/no run....cars are more than electrical diagrams, it would seem
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Offline daveismissing

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Re: Coolant Temps sensor
« Reply #6 on: June 18 2019, 10:47:49 AM »
The reading was high resistance -a few hundred K - scanner showed neg 30 F.

The resistance did change with temperature but off by a suspicious factor of about 100, made me doubt myself the meter or the chart.

Changed meters and plopped a 2K resistor across the harness- gave me a nice 90 deg F reading, so we know the chart and meter are correct.

PS: later discovered Mouser have the Delphi  part under the GM part number, the advantage would be cheap overnight shipping to most places.


-Drain plug by Earl Brown, custom oil pan by Rich's Auto

 

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