Overheating Issue
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Joined: Aug 2020
Posts: 84
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From: Arizona
Overheating Issue
Evening team!
so I ran into an issue some weeks ago, and eventually gave up after running through you scenario. Began to have my coolant gauge dancing from cold to overheating, immediately I know gaskets are fine as it dances. At first it only happen at rare occasions but now it begins to dance up and down within 15 minutes of running. I change out the coolant sensor hoping that would fix my problem but it did not. Not much of a wiring guy so I immediately hit a wall with it.
If I can get any other scenarios to run, I would greatly appreciate !
least before I decide to take to a shop
so I ran into an issue some weeks ago, and eventually gave up after running through you scenario. Began to have my coolant gauge dancing from cold to overheating, immediately I know gaskets are fine as it dances. At first it only happen at rare occasions but now it begins to dance up and down within 15 minutes of running. I change out the coolant sensor hoping that would fix my problem but it did not. Not much of a wiring guy so I immediately hit a wall with it.
If I can get any other scenarios to run, I would greatly appreciate !
least before I decide to take to a shop
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,426
Likes: 3,979
From: Cape Coral, Florida
The ECT circuit is a basic 2 wire thermistor...the yellow wire is your signal wire and you have a sensor ground being the other...with the connector unplugged you should see a 5 volt reference on the yellow wire with the key on...the ECT sensor you changed will pull that 5 volt ref. to ground depending on the coolant temp...when the coolant temp rises the resistance decreases... if you were to take the 2 wires and jump them together you will see 280 degrees...just connector unplugged you will see -36 degrees...that yellow wire is most likely shorted to ground (chaffed wire to the metal frame) or to each other and that is why you are seeing the ECT jump around like that...you will have to inspect the ECT wires !!
Last edited by C5 Diag; Jul 1, 2021 at 03:28 PM.
Thread Starter
Advanced
Joined: Aug 2020
Posts: 84
Likes: 2
From: Arizona
The ECT circuit is a basic 2 wire thermistor...the yellow wire is your signal wire and you have a sensor ground being the other...with the connector unplugged you should see a 5 volt reference on the yellow wire with the key on...the ECT sensor you changed will pull that 5 volt ref. to ground depending on the coolant temp...when the coolant temp rises the resistance decreases... if you were to take the 2 wires and jump them together you will see 280 degrees...just connector unplugged you will see -36 degrees...that yellow wire is most likely shorted to ground (chaffed wire to the metal frame) or to each other and that is why you are seeing the ECT jump around like that...you will have to inspect the ECT wires !!
