Aux Coolant Pump
E53 2005 4.4i. Noticed heating was not effective as it used to be. After checking out I found out the Aux pump motor is not running to circulete coolant through the cabin heater.
The pump, wiring connectors seems good. I am getting the reference voltage of 5.2v at the connector from ECM. Ocationaly I get the battery voltage and the pump would run for a second or two.
It seems like a sftware issue. I am thinking of disconnecting battery for a time to reboot
I could not do any diagnostics with PA Soft 1.4.0. I could not get Inpa software running at all
Please advise. It is so cold in Canada at this time.