Friday, October 5, 2012

Faulty coolant level sensor

Faulty coolant level sensor on Pontiac Grand Prix 

Problems Noticed Will Be:----

  • The on dash coolant light blinks ON & Off.

You Can Try:---

Remove the coolant sensor and clean it with electronic component cleaner,then refit the sensor and see.
In most cases this helps.

But if that is not helping then,may be its faulty coolant level sensor.

There is a testing procedure to Test the Sensor:----

These procedure helps to confirm if sensor is faulty or not.

  • First of all you have to remove the low coolant level sensor.
  • Now with the ignition key on but the the engine off and the coolant level sensor disconnected from the vehicle wiring harness, observe the low coolant light:

               A)  Light is on - Chassis wiring or instrument cluster concern. Follow the appropriate diagnostic information in SI.
               B)  Light is out - Proceed to Next Step of Testing Procedure.

See the diagram shown below for more help:------

low coolant level sensor


  • Now With the key off, you have to connect the coolant level sensor into the vehicle's wiring harness. 
  • The connection should be as follows.The above diagram will be helpful.As per the diagram connect a ground wire (1) to the battery negative terminal. Using a sharp probe (3) attached to the ground wire, ground the coolant sensor probe (2) as shown in the illustration. 
  • The wire contact should not be loose.Make sure a good contact is made. Once this wiring connections are done.Now with the key on and the engine off, observe the low coolant light for at least 15 seconds.

          A) If the Light is still on - Replace the low coolant sensor and re-check system operation.
          B) But if the Light is out - Proceed to Next Step.

  • Try cleaning the sensor.For that you can use a small wire brush or emery cloth, polish the low coolant level sensor probe to remove any film or oxidation. 
  • A indication of good sensor is that the probe should be a bright brass color when finished. Use Brake Parts Cleaner to flush removed deposits from the low coolant sensor probe. Re-install the low coolant sensor into the vehicle and proceed to Next Step.

  • Now before re-installing the same old coolant sensor.Without forget clean the coolant system of the car. And for that you have to flush the cooling system and install new DEX-COOL(R) mixture as outlined in the SI. 
  • Without forget check the vehicle's warranty history to determine if any engine gasket had recently been changed. If there has not been a recent gasket replacement, locate and repair the source of the engine oil contamination.
  • In most of such cases,the low coolant level light comes on due to engine oil getting collected and contaminated on vehicles sensors and other parts.

In case if the coolant level sensor is checked to be faulty,then please go for branded part,instead of cheap non branded parts.
The non-branded aftermarket parts are not bad parts,but there performance is very low/less as compared to genuine/original branded parts.

These details will help.

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