Thermostat Housing
Engine Valve Cove
Intake Manifold
Expansion Tanks
Variable Valve Timing (VVT)

EGR Valve
Secondary Air Pump
Oil Cooler
Blower Resistor
Heater Valve
Throttle Body
Ignition Coil
Nitrogen Oxygen Sensor
Headlight Leveling Sensor
Oxygen Sensor
Temperature Sensor
Brake Light Switch
Fuel Pressure Regulator
Mass Air Flow Sensor
Oil Pressure Switch
ABS Sensor
Auxlliary Water Pump

Heater Valve (HVAC heater,heater control valve)

What is a Heater Control Valve all about?
The heater control valve is responsible for warming the interior compartment. This valve controls the flow of coolant from the engine to the heater core. Most heater control valves are operated in three basic ways. A manual cable, a thermostat type system, or even engine vacuum can control them.

How it's done:
Pressure check the cooling system.
Test operation of the valve .
Replace the control valve if bad/leaking.
Fill with coolant.
Test operation of the heater.

Failure Symptoms
Coolant is leaking.
Heater does not work.