EGR Valve
Secondary Air Pump
Thermostat Housing
Oil Cooler
Fuel Pressure Regulator
Blower Resistor
Heater Valve
Ignition Coil
Air Flow Sensor
Headlight Leveling Sensor
Lambda Sensor
Temperature Sensor
ABS sensor
Brake Light Switch
Oil Pressure Switch
Throttle Body
Auxiliary Water Pump

Heater 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.