Thanks for using Just Answer. I would be glad to assist you.
Is the coolant light still on?
Are you asking how to fix the coolant light or if the dealer's diagnostic process was accurate?
The Visa card I used is a refund from AT&T which can be used by anyone accepting Visa and must be used as a credit card. Let me know if there is a problem.
There was an error with your transaction. Here's the error that was given by our credit card processor: [C] Invalid response from gateway: 530.
It sounds like they followed the correct diagnostic process. I will explain the process that I would use to diagnose your issue, which should be close/identical to the process that the technician used. Please refer to the diagrams below and I will walk you through the diagnostic process step by step:
I would begin by checking the resistance across the coolant level sensor to make sure the resistance is good. If the resistance is out of range, I would replace the coolant level sensor.
Next I would check the connector pin # XXXXX (connector C3) on the BCM to see if it is recieving signal from the coolant level sensor.
If there is no signal, and the light is on, then I would continue checking the system (see next step).
If there is no signal, and the light is on, then I would test the pin #19 (connector C4) on the BCM. This wire controls signal to the instrument panel. If this wire is sending a signal, then I would replace the BCM. If not then I would continue checking the system.
Next I would check the wire going from the BCM pin # XXXXX to the cluster. If the wiring and the BCM was good, then I would replace the instrument cluster.
Please let me know if there is anything else I can do to assist you.