Change in Thermostat Electrical Connector on Replacement Engine Harness. Vehicles produced from 3/2013 are no longer equipped with an engine coolant thermostat that incorporates the engine coolant temperature sensor (thermostat P/N 11 53 7 647 751). The engine coolant temperature sensor is now an individual component. To accommodate this component change, there was also a production change to the engine wiring harness; this also includes the replacement engine harnesses for earlier produced vehicles. The replacement harness is no longer equipped with the four pin connector for the thermostat / engine coolant temperature sensor, but two separate twopin connectors, one for the coolant thermostat and one for the engine coolant temperature sensor. *The N16 engine switched production to the 11 53 7 534 521 thermostat in 3/2012. This thermostat, like the new 751, incorporates a separate engine coolant temperature sensor. The connectors on the 521 thermostat will not match up to the connectors on a new, replacement engine harness. The 521 thermostat will need to be replaced with the 751 thermostat during this repair.
