06/04/2023
Spent my Sunday sleuthing out a no heat condition on a 2012 Volt. After a review of the three coolant pump system on the car, I focused on the heater pump which had a code. After a running the ICE engine, this car still had no heat which meant a deeper look at diagnosing the circuit. Analysis of the Remote HVAC module revealed a flicker of data from 0Hz to20Hz AND 0%to 100% in the feed back loops. Checking the power supply revealed the fuse was missing. This car had been acquired from the action which is a place where anything goes. Including borrowing fuses from from one car to another. No codes and heat now.