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Hi, disconnect the coolant sensor and measure across the pins of the sensor with an ohmmeter. You should measure 110 ohms.
Let me know what you find.
Ok, that reading is fine. Can you measure the washer fluid level sensor? It should measure 160 ohms. We may need to get to the plug at the instrument cluster and do some tests from there.
If you disconnect the coolant level sensor will the light turn off?
Ok, you are going to need to remove the instrument cluster and measure the resistance between terminal 4 and 12 in connector 1 section B. I've attached a picture below of the connectors. You should measure approximately 270 ohms with the connector disconnected. If you have the proper resistance at the plug the problem is in the instrument cluster or there is a poor connection at the plug.